Transducer/flexure/conductor structure for electromagnetic read/write system

ABSTRACT

Flexure/transducer structure employable in an electromagnetic information storage and retrieval system wherein mechanical load-bearing responsibilities and electrical-current-carrying responsibilities are merged into and shared by common structure. The invention subject matter is useable in systems characterized by contact operation, as well as by quasi-contact and noncontact operations, in relation to the recording surface in an information recording medium.

This is a continuation-in-part of U.S. patent application Ser. No.08/191,967 (now abandoned) which was filed on Feb. 4, 1994, which was acontinuation-in-part of U.S. patent application Ser. No. 07/919,302 (nowabandoned) which was filed on Jul. 23, 1992, which was acontinuation-in-part of application Ser. No. 07/806,611, now U.S. Pat.No. 5,174,012 which was filed on Dec. 12, 1991 and issued on Dec. 29,1992, which was a continuation of application Ser. No. 07/632,958, nowU.S. Pat. No. 5,073,242 which was filed on Jul. 24, 1991 and issued onDec. 17, 1991, which was a continuation of application Ser. No.07/441,916, now U.S. Pat. No. 5,041,932 which was filed on Nov. 27, 1989and issued on Aug. 20, 1991. This is also a continuation-in-part of U.S.patent application Ser. No. 07/990,005 (now abandoned) filed Dec. 10,1992 which is a continuation of U.S. patent application Ser. No.07/746,916 (now abandoned) filed on Aug. 19, 1991. Additionally, this isa continuation-in-part of 07/966,095 now issued as U.S. Pat. No.5,550,691, which was filed on Oct. 22, 1992 and issued on Aug. 27, 1996which is a continuation-in-part of Ser. No. 07/783,509 (now abandoned)filed Oct. 28, 1991. Further, this is a continuation-in-part of U.S.patent application Ser. No. 07/783,619 now issued as U.S. Pat. No.5,490,027 filed on Oct. 28, 1991 and issued on Feb. 6, 1996. This isalso a continuation-in-part of U.S. patent application Ser. No.08/179,758 (now abandoned) filed on Jan. 7, 1994, which is acontinuation of U.S. patent application Ser. No. 07/684,025 (nowabandoned) filed on Apr. 10, 1991. This is also a continuation-in-partof U.S. patent application Ser. No. 08/017,984 (now abandoned) filed onFeb. 12, 1993, which is a continuation from U.S. patent application Ser.No. 07/770,593 (abandoned) filed on Oct. 3, 1991. This is also acontinuation-in-part from U.S. patent application Ser. No. 08/180,540(now abandoned) filed Jan. 12, 1994, which is a continuation-in-partfrom U.S. patent application Ser. No. 07/760,586 (now abandoned) filedSep. 16, 1991. The following U.S. patent applications and patents areincorporated by reference into this application: Application Ser. No.07/911,680, U.S. Pat. No. 5,041,932, application Ser. No. 07/990,005,application Ser. No. 07/746,916, application Ser. No. 07/966,095, U.S.Pat. No. 5,550,691, application Ser. No. 07/783,509, application Ser.No. 07/783,619, U.S. Pat. No. 5,490,027, application Ser. No.08/179,758, application Ser. No. 07/684,025, application Ser. No.08/017,984, and application Ser. No. 07/770,593.

FIELD OF THE INVENTION

The present invention relates to electromagnetic read/write, informationstorage and retrieval systems, and in particular, to the structuralmerging in such systems of electrical and mechanical functionality, andto ancillary matters that surface as structural, organizationalopportunities as a result of such merging. Recognizing that the variousfeatures of the invention can have important applicability in a widerange of kinds of such systems (e.g., rigid-disk, floppy-disk, drum,tape, etc. systems), the description which follows herein focusesattention on rigid-disk systems—an arena which is most central intoday's commercial applications. Accordingly, specification and claimreferences made herein to rigid disks should be read to include theseother-kinds-of-media systems.

Given the merged-functionality aspect of the present invention, manyfeatures thereof, accordingly, focus upon improvements in mechanicalload-bearing and in motion-articulating characteristics of transducers,and of flexures which carry such transducers, that are used in thesekinds of systems. In this context, the field of the inventionencompasses systems wherein (a) a read/write transducer flies over amedia recording surface, (b) such a transducer is intended forcontact-capable operation, and operates with intermittent media-surfacecontact, and (c) such a transducer is intended for contact-capableoperation, and operates in substantially continuous contact with a mediarecording surface.

BACKGROUND AND SUMMARY OF THE INVENTION

In the march of progress which has characterized ongoing development ofdisk-drive, electromagnetic read/write systems, the quests forenlargement of a real recording density, and for improved-qualityread/write signal communication between a disk's recording surface and atransducer, have been high on the list of technical interest andrelentless pursuit. This situation has been reflected, inter alia, insignificant reductions in components' sizes and masses, by reductions inthe “effective masses” of those components which react dynamicallyduring read/write operations, and in dramatic reduction in theseparation which exists between the working read/write zone of atransducer and a disk's recording surface. These advances include,according to an important line of development by the Censtor Corporationof San Jose, Cali., system embodiments in which a read/write transduceroperates in substantially continuous sliding contact with such arecording surface. The latter line of advancement in the art ofdisk-drive recording is well illustrated and expressed in the parentpatent and patent applications which have been set forth hereinabove.

Pausing for a moment at this point to focus upon prior art efforts byothers to bring about size reductions, it is important to bear in mindthat these prior art changes have, by and large, been accomplished withwhat might be thought of as a segregated rather than a merged focus uponthe three core functionalities—electrical, mechanical and magnetic—ofread/write transducers and supporting flexures. In other words, priorart thinking has looked upon the respective components in thisenvironment which offer each of the individual functionalities as beingessentially independent of the other-functionality components. As aconsequence, there has been somewhat of a naturally perceived limit inhow far one can go to bring about significant size reduction—a limitdictated by functional performance constraints, and even moreappreciably, probably, by manufacturing-costs andmanufacturing-capabilities constraints.

Specifically, and looking for a moment just at the issue of mechanicalload bearing, prior art thinking has been based upon the notion thatonce necessary mechanical load-bearing requirements are known, all ofthat structure which has been looked upon in the past as being the soleconstituent attending to that functionality can only be reduced in sizejust so much if it is to remain practically manufacturable. However,beginning with the work of Hal Hamilton as such is expressed in theabove-referred-to '932 patent, a new kind of thinking has entered thisart, whereby “merger of functionality” is viewed as providing anopportunity for retaining all necessary electrical, mechanical andmagnetic capability, while at the same time allowing for substantialshrinking of overall size, and actual improvement in practicalmanufacturability. More particularly, in the Hamilton '932 disclosure,there surfaces a recognition that electrical current-carrying structurecan be utilized significantly to carry mechanical load, and conversely,that mechanical load-bearing structure can be utilized significantly tocarry electrical current. In other words, what might be thought of assingular-character structure, or material, functions in multiple ways.Not only does this unique way of thinking about merged-functionalityyield surprising size- and mass-reduction opportunities, but also ittends to lead toward structures which are inherently simpler in form andin construction, and less complex and costly to fabricate.

It is this “merged-functionality” view which underlies key contributionsmade to the art by the present invention.

Continuing, and directing attention to other matters upon which thisinvention is focussed, in the ever more intimate environment of theinterface between a disk's recording surface and a read/writetransducer, and in addition to the size, mass, effective mass andspacing issues just generally expressed, many other considerations sitas important participants at the table of key technical concerns. Forexample, tight control over, and maintenance of, a very precise XYZspacial location of a transducer in relation to a disk surface iscritical, as is the ability of the transducer and supporting flexurestructure to respond rapidly and fluidly to disk-surface topographicalfeatures, and/or to other things and events which require speedy,accommodating, operating-attitude adjustment. This kind of adjustmentmust take place in a manner minimizing as much as possible any occasionsof signal-communication drop-out, and in a manner free of disruptiveresonance vibrations. Attention also must be addressed to damping andshock-absorbing issues.

All of these considerations need to be taken into account as well (a) insystems where a transducer flies over a disk's recording surface, (b) insystems where contact operation occurs (intermittently or continuously),and (c) in systems which, on the one hand, have gimbaled transducerstructures, and on the other hand, non-gimbaled transducer structures.

In the gimbaled transducer setting, the merged functionality focusaspect of the invention opens the door to the fabrication and use of aload-bearing transducer chip which has a substantially planar body, withplural, projecting disk-surface contact feet, or pads, and which canoperate, relative to a disk's recording surface, with substantially azero-angle-of-attack, and with the read/write portion of the transducerin intimate contact with that surface. This, in turn, offers theopportunity for electromagnetic design which occupies space in the planeof the body, and which allows for placement of the read/write zoneanywhere relative to that body.

Given the above remarks and comments, it is an important object of thepresent invention to offer transducer/flexure improvements along thelines just suggested —focused on the notion of structural merging, forexample, of electrical and mechanical functionality.

A related object of the invention is to provide such improvements whichlead toward simple, low-cost, low-mass structures that offer theopportunity for appreciable enlargement in areal density of recordedinformation, with reliable and improved signal-communicationcharacteristics.

Thus, an important object is to provide a head/flexure structure whichincludes load-bearing (merged-functionality) conductors.

A related object is to provide a head/flexure structure in which theconductors perform mechanical functions in addition to their function ofconducting electrical signals between a head and other circuitry.

Still another object of the invention disclosed herein is to provide aflexure/conductor structure which supports a head in a precise locationand orientation relative to the surface of a medium.

Yet a further invention object is for the head-supporting flexure to becapable of supporting the head in a contacting relationship with thedisk while reading or writing, without the occurrence of catastrophichead crash events or excessive interface wear.

Also, an object of the invention is to provide a flexure/conductorstructure which is capable of moving the head along a Z-axis, i.e., thataxis which is normal to the surface of the disk, with a minimal degreeof angular rotation, i.e., minimizing the angular constant.

Another object is to provide a flexure/conductor structure whichexhibits maximum levels of lateral and torsional resonant frequencieswith the minimal amount of gain.

Still a further object is to provide a transducer/flexure/conductorstructure which has a minimal number of parts, and which can be producedby a relatively straight-forward and cost-effective process, including,in certain cases, an automated assembly process.

Another object is to provide a flexure/conductor structure which iscapable of compensating for topographical irregularities in the surfaceof the recording medium.

Yet another object of the invention is to provide a flexure/conductorstructure in which the head is allowed a certain range of pitch and rollmovement independent from the flexure.

A further object is to provide a head/flexure structure which has atunable hinge near its proximal end.

Other objects include providing a head/flexure structure which: (a) iswireless; (b) is amenable to compact disk-to-disk stacking; and (c)contains more than one pair of conductors.

Still a further object is to provide a head/flexure structure which hasa gimbal including conductive articulators.

Thus, the inventive subject matter presented herein regards improvementsin transducer/flexure structure for an electromagnetic read/writesystem, and relates, inter alia, to structures, such as flexures, forcarrying electromagnetic read/write transducers, and more particularly,to such structures wherein electrical conductors which connect with suchtransducers are utilized significantly, in an augmentive way, asmechanical load-bearing and articulating elements in the structures. Thesubject matter of the invention also relates to contact-capableread/write systems in which the read/write transducer acts directly as aload-bearing structure under disk-contact conditions. According to animportant aspect of the invention, therefore, such augmented-roleconductors play the dual roles of (a) conducting electrical signalsbetween a transducer and remote, external circuitry, such as a signalprocessor, and (b) at the same time supporting mechanical load (such asa bending and/or articulating load), including, in certain embodiments,100% of that load in a certain portion or region of atransducer-carrying structure.

Fundamentally, the subject matter of the present invention rests onseveral key concepts, some of which spring from the notion thatinnovation in the load-carrying/articulation characteristics oftransducer-carrying structure can significantly enhance overallread/write system performance. One of these concepts—based upon a newand striking “merged-functionality” recognition—is that the very sameconductors which carry signal-bearing information to and from aread/write transducer can also function mechanically as the articulatingand load-bearing beam structure which carries and supports such atransducer, statically and dynamically, for instance, in the setting ofa cantilever-type support arrangement for a disk read/write transducer.This conceptual thought carries also into an arrangement where,effectively, the transducer is supported for gimbaling action, with therecognition that what might be thought of as the gimbal articulators(hinges or torsional beams) can be formed by electrical-current-carryingconductors.

Another foundation concept is that the flexure/beam transducer-carryingconstruction can take important advantage of what can be viewed asbilateral motion independence, wherein a pair of spaced beam componentsafford a single- or dual-axis articulation capability to a supportedtransducer. Indeed, such construction can enable dual-degree-of-motiongimbal action (as just suggested above) for such a transducer. The shiftof mechanical articulation and load-bearing responsibilities tosignal-carrying conductors is an especially useful concept in so-calledmicro-flexure designs where extremely small mechanical structures areinvolved.

A further important concept is that a read/write transducer can itselfbe utilized as a load-bearing structure—a concept leading, inter alia,toward minimizing of the size and mass of the overalltransducer/flexure/conductor structure.

In addition to the structural contributions made by the presentinventive subject matter, also furnished thereby are novel methods ofproducing micro-transducer-support structures employing signal-carryingconductors as mechanical load-bearing/articulating elements such, forexample, as hinges, torsional beams, etc.

These and other objects, advantages and features that are offered by thepresent invention will become more fully apparent as the descriptionwhich now follows is read in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are views of a transducer/flexure which is disclosed andclaimed in U.S. Pat. No. 5,041,932. FIG. 1A is a side view of thetransducer/flexure, loaded on a disk, in relation to an XYZ coordinatesystem. FIG. 1B is a cross-sectional view of the flexure shown in FIG.1A, with this view being taken generally along line 1B—1B in FIG. 1A.

FIG. 2 is an exploded perspective view of a tapered transducer/flexurestructure with load-bearing conductors and a hinge.

FIG. 3A is a top view of the transducer/flexure shown in FIG. 2.

FIG. 3B is a partial side view of the distal end of thetransducer/flexure shown in FIG. 3A.

FIG. 3C is a bottom view of the transducer chip shown in FIG. 3B.

FIG. 3D is an enlarged, fragmentary view of the area in FIG. 3B embracedby curved arrows 3D—3D, illustrating a modified form of transducer poleand coil structure.

FIG. 4 is a partial top view of a flexure, focusing on the hinge region.

FIG. 5A is a cross-sectional view of the flexure shown in FIG. 3A.

FIGS. 5B and 5C are cross-sectional views of flexures with load-bearingconductors and additional damping and constraining layers.

FIG. 6 is a partial side view of the flexure shown in FIG. 3A, focusingon the hinge region.

FIG. 7 is a schematic partial view of a flexed beam with an interveningadhesive resin layer.

FIG. 8 is an exploded perspective view of a transducer/flexure with fourconductors, and a hinge near the proximal end of the flexure.

FIG. 9 is a top view of the transducer/flexure shown in FIG. 8,assembled. Conductor boundaries, which are covered by stiffeners, areindicated by dashed lines.

FIG. 10 is an exploded perspective view of a transducer/flexure withload-bearing conductors and a load-button gimbal.

FIG. 11 is a perspective view of the transducer/flexure shown in FIG.10, assembled except for mounting of the chip (transducer).

FIG. 12A is a top view of the transducer/flexure shown in FIGS. 10 and11. Conductor boundaries, which are covered by stiffeners, are indicatedby dashed lines.

FIG. 12B is a partial side view of the distal end of the flexure shownin FIG. 12A.

FIG. 12C is a bottom view of the transducer shown in FIG. 12B.

FIG. 13 is an exploded perspective view of a transducer/flexure withload-bearing conductors, a hinge near the proximal end of the flexureand a gimbal near the distal end of the flexure.

FIG. 14 is a partial top view of the conductors shown in FIG. 13,focusing on the distal ends of the conductors, specifically, theconductor gimbaling structure.

FIG. 15A is a top view of the transducer/flexure shown in FIG. 13,assembled.

FIG. 15B is a partial side view of the transducer/flexure shown in FIG.15A.

FIG. 15C is a bottom view of the transducer shown in FIG. 15B.

FIG. 15D is a partial side view of the distal end of a gimbaledtransducer/flexure with a modified transducer and pad configuration.

FIG. 15E is a bottom view of the transducer shown in FIG. 15D.

FIG. 16 is a thin-layer sectional view of the flexure shown in FIG. 15A.

FIG. 17A is a partial top view of the distal end of thetransducer/flexure shown in FIG. 15A, with the addition of a membranedamping layer in the vicinity of the gimbal.

FIG. 17B is the same as FIG. 17A except the damping layer is localizedover four discrete regions of the gimbal.

FIG. 18 is a partial top view of the distal end of a transducer/flexurewith a membrane which functions primarily as a gimbal structure.

FIG. 19A is a top view of a transducer/flexure with load-bearingconductors, two hinges and a modified gimbal.

FIG. 19B is a partial top view of the distal ends of the conductors inthe transducer/flexure shown in FIG. 19A.

FIG. 20 is a side view of the transducer/flexure shown in FIG. 19A,operating on a disk.

FIG. 21 is a top view of a transducer/flexure, similar to the one shownin FIG. 19A, except that conductor dimensions are modified.

FIG. 22A is a side view of the transducer/flexure shown in FIG. 21, witha pre-bend near the proximal end of the flexure. The flexure is shown inits pre-loaded position (solid lines) and in its operating orloaded-position (dash-dot lines).

FIG. 22B is a partial top view of a flexure which is similar to theflexure shown in FIG. 21, except that it employs a modified gimbal.

FIGS. 23-25 are top views of modified two-conductor gimbalingstructures.

FIG. 26 is a top view of a modified four-conductor gimbaling structure.

FIG. 27A is a partial top view of a two-conductor gimbaling structurethat forms part of a transducer/flexure which employs hinges to allowroll and pitch movement of the chip.

FIG. 27B is a partial top view of the gimbaling structure shown in FIG.27A, with the addition of stiffening layers.

FIG. 28A is a top view of a first embodiment of a torsionally complianttransducer/flexure.

FIG. 28B is a side view of the transducer/flexure shown in FIG. 28A.

FIG. 29A is an exploded perspective view of a second embodiment of atorsionally compliant transducer/flexure, with a pitch gimbal mechanism.

FIG. 29B is a top view of the transducer/flexure shown in FIG. 29A.

FIG. 30 is a top view of a third embodiment of a torsionally complianttransducer/flexure with a pitch gimbal.

FIG. 31 is an exploded perspective view of a dual-cantilevertransducer/flexure with four conductors and four hinges.

FIG. 32 is a perspective view of the transducer/flexure shown in FIG.31, assembled.

FIG. 33 is a side view of the transducer/flexure shown in FIGS. 31 and32. The flexure is shown in its pre-bent unloaded position (solidlines), and in its loaded or operating position (dash-dot lines).

FIG. 34A is an exploded perspective view of another dual-cantilevertransducer/flexure.

FIG. 34B illustrates the transducer/flexure of FIG. 34A, assembled.

FIG. 34C is a schematic side view of the transducer/flexure shown inFIGS. 34A and 34B, in its unloaded position (dash-dot lines) andoperating position (solid lines).

FIG. 35 is an exploded perspective view of another transducer/flexureembodiment.

FIG. 36A is an exploded perspective view of still anotherdual-cantilever transducer/flexure embodiment.

FIG. 36B is a partial side view of the distal end of thetransducer/flexure shown in FIG. 36A.

FIG. 37A is a schematic side view of a disk-contacting mountconfiguration supporting a transducer/flexure in its operating position.

Each of FIGS. 37B and 37C is a top view of a transducer/flexure of thepresent invention including an alternative gimbal design.

FIG. 38A is a schematic side view of a flexure mounting system showingdisk-to-disk spacing with respect to an E-block and mounted flexures.

FIG. 38B is a schematic side view of a modified flexure mounting systememploying dual-cantilevers to permit closer disk-to-disk spacing.

FIG. 38C is a partial side close-up view of one of the flexures anddual-cantilever mount structures shown in FIG. 38B.

FIG. 39A is a schematic top view of a transducer/flexure mounted on anut plate and including a two-conductor configuration with versatile,redundant connective tabs on opposite sides with the proximal end of theflexure/nut-plate structure.

FIG. 39B is a schematic side view of four flexure/nut-plate structuresas shown in FIG. 39A, mounted in an E-block and electrically connectedto a flex cable.

FIG. 39C is a schematic top view of another nut-plate/flexure embodimentwith versatile, redundant connector conductor tabs.

FIG. 40A is a top view of a gimbaled flexure embodiment which isdimensioned to operate under a minimal load.

FIG. 40B is a top view of the conductor configuration employed in theflexure shown in FIG. 40A.

FIG. 40C is an enlarged partial top view of the flexure shown in FIG.40A.

FIG. 40D is a schematic side view of a transducer/flexure with apre-bend near its distal end.

FIGS. 41-45 are schematic top view layouts of sheet intermediatematerials used in a production method of the present invention.

FIG. 46 is a top view of a flexure resulting from the processillustrated in FIGS. 41-45. Relative dimensions of the final flexurestructure are shown.

FIGS. 47-49 are schematic top view layouts of sheet intermediatematerials used in another production method of the present invention.

FIGS. 50A and 50B show working-side views of two modified forms oftransducer chips.

DEFINITIONS

Terminology in the specification and claims should be interpreted inaccordance with the following definitions.

A “flexure” is a flexible cantilever beam, with or without gimbalstructure, for supporting a transducer adjacent a medium. A “suspension”may refer to a flexure, either alone or together with a flexure mountingsystem.

A “transducer” is an electromagnetic working organization, or unit,employed typically near the distal end of a flexure directly adjacent amedium in a read/write system. The transducer includes pole and coilsubstructures and the embedding material surrounding the substructures.A pole has a read/write working region. As used herein, the transducerdoes not include ancillary joined structure such as air bearing rails ina conventional flying slider. In at least one embodiment of theinvention, the transducer is provided as an integrated component of theflexure. In other embodiments, the transducer is in the form of a chipwhich is joined to the distal end of the flexure. Each transducer has aworking side which faces the recording surface in a magnetic mediumduring normal read/write operations.

At various locations throughout this specification reference is madeselectively to the top and bottom sides of different structures. Wherethese terms are applied to a disk surface, it is assumed that therelated disk is operating in a horizontal plane. Where these terms areapplied to flexure, beam, transducer structures inside of thetransducer, and top side refers to the opposite side.

The “Z-axis” is perpendicular to the surface of a recording medium andextends vertically through a transducer mounted on the free end of aflexure. A limited range of movement of the transducer along the Z-axisis allowed, as the transducer follows disk surface topography, duringand between reading and writing activity. An “X-axis” and a “Y-axis”share a common origin with the Z-axis at the center of the distal edgeof the transducer, and are perpendicular to each other in a plane whichis co-planar with the upper-most surface of the medium when thetransducer is operating in contact with this surface. The Y-axis isgenerally “longitudinal”, i.e., parallel to the length of the flexure.The X-axis is generally “lateral”, i.e., parallel to the width of theflexure. The X, Y and Z axes are illustrated in FIG. 1A relative to thedistal tip of a transducer/flexure 60. The point of contact 62 betweenthe transducer and disk 64 coincides with the origin of the coordinatesystem.

“Roll”, “pitch” and “yaw” refer to particular types of inclinationalmovement of a transducer relative to its static or idealized suspendedposition adjacent the surface of a medium. “Roll” refers to rotationalmovement about the Y-axis of a transducer adjacent the surface of arecording medium. “Pitch” refers to rotational movement around theX-axis of a transducer adjacent the surface of a recording medium. “Yaw”refers to rotation around the Z-axis of a transducer adjacent thesurface of a recording medium.

“Load-bearing” is defined and used, inter alia, in the context of acantilever flexure which has a mounting end and a free end extendinggenerally horizontally over (adjacent) the surface (upper or lower) of arecording medium, for example, a rigid disk. The free end of the flexuresupports and positions a transducer for reading and writing informationon the surface of a medium. By deflection, the free end (distal end) ofthe flexure is applied by a force (load) against either the surface ofthe medium or an air-bearing directly on top of the surface. Elements ofthe flexure which provide significant support for the load, i.e.,maintenance of desired Z-axis position of the transducer, are referredto as “load-bearing” structures. “Load-bearing” also relates to“articulation” (defined below) structure.

A “beam” is a transverse structural member which provides partial orcomplete support for a transducer adjacent the surface of a recordingmedium. The term “beam” may be used referring to the entire flexurebody, or a load-bearing component of the body.

“Anisometric” means inequality of measurements or properties. The termis used in this application with reference to a beam'saxis-differentiated bending stiffness—i.e., regarding a beam having apreferential bending axis.

“Articulation” is used with respect to two structural members (sometimesreferred to as “arms”) which are linked together, but allowed a certaindegree of movement relative to each other. An “articulator” is asemi-rigid structure connecting first and second parts, which permits aselected range and type of mechanical movement of the parts relative toeach other. An “articulating conductor” is an electrical conductor whichalso functions as an articulator. A “hinge articulator”, also referredto as a “beam/articulator structure”, is an articulator (unit, element)which bends around an axis perpendicular to a line centrally anddirectly connecting the two parts (also referred to as a “longitudinalaxis”). A “torsional articulator” is an articulator (unit, element)which twists around an axis centrally and directly connecting the twoparts (longitudinal axis). A “torsional beam” is a torsionalarticulator. A “mixed-mode articulator” (unit, element) is a hybrid of ahinge articulator and a torsional articulator.

“Hinge” is a connector between two parts which allows a degree ofmovement, i.e., bending, of the parts relative to each other.

“Proximal” is used to refer to the end vicinity of a flexure which isstructurally anchored or secured to a read/write system frame orservo-control actuator. The proximal end of the flexure is also referredto as the “mounting end”.

“Distal” is used to refer to the end vicinity of the flexure whichcarries the transducer and is also referred to as the “free end”.

“Angular constant” is defined, relative to a cantilever flexure, as thedegree of angular change at the distal tip of the flexure for a givendeflection.

A “pad” (also referred to as an island) projects from a side or face ofa flexure or a transducer chip and contacts the surface of a disk whenthe transducer/flexure is operating to read or write information fromthe disk. With respect to flexures which employ gimbals, a triangularorganization of three pads is sometimes used, and referred to as a“tripad” or “trident” structure.

DETAILED DESCRIPTION OF INVENTION

The invention, resting strongly on the merged-functionality concept setforth above, involves load-bearing and articulating structures for usein suspensions relating to micro-flexures which support transducers inelectromagnetic read/write systems. These structures take the forms ofload-bearing conductors and transducers, hinge-like mechanisms,torsional beams, and flexure mounting systems which allow production andimplementation of flexures with low angular constants, minimum mountingtolerances, and/or the capability of tolerant compliance of thetransducer with an inherently irregular recording medium surface: Animportant aspect of some of the transducer/flexures disclosed andclaimed in the present invention is the use of electrical conductors andtransducers which are geometrically designed and arranged to provideload-bearing support, as well as articulable movement, between linkedportions of the flexure body.

FIGS. 1A and 1B illustrate a micro-flexure 60(flexure/conductor/transducer structure), including an integratedtransducer, or transducer unit, which was originally described andclaimed in parent U.S. Pat. No. 5,041,932. The transducer, which is atiny portion of the overall structure pictured in FIG. 1A, is located atthe distal tip shown at 62. This transducer includes magnetic polestructure and coil and conductor structure all embedded in a smallvolume of surrounding joinder structure. It is in the disclosure of the'932 patent that the notion of merged-functionality makes its importantdebut in the read/write, disk drive transducer/flexure context. It isalso in the '932 patent that one finds the introduction of aload-bearing transducer unit. Reference to the text and drawings of thepatent will reveal a novel transducer unit having pole structure unifiedwith (and within) a disk-contacting wear pad (or projection), andgenerally planarly distributed, coupled coil structure which extendsgenerally in a plane parallel with the plane of the wear pad'sdisk-contacting face.

As shown in FIGS. 1A and 1B, micro-transducer/flexure 60 includesintegrated load-bearing conductors 61 a and 61 b embedded within flexure60 along its entire length (continuum structure). An integratedtransducer is embedded within flexure 60 at its distal tip 62 where itcontacts disk 64 during operation of the read/write system. A number ofimportant features of the present invention, which are more extensivelydeveloped in the embodiments illustrated and described below, are fullypresent in the micro-transducer/flexure structure illustrated in FIGS.1A and 1B. First, as shown in FIG. 1B, integrated conductors/beams 61 aand 61 b are massive enough relative to the entire flexure body 60 tosupport a significant portion of the cantilever load. According to theteachings of the '932 patent, conductors 61 a, 61 b occupy in the rangeof about 13% to about 40% of the full thickness of the body of flexure60. Therefore, conductors 61 a and 61 b play a dominant mechanical role,and are referred to as “load-bearing conductors”. Another importantphysical attribute of conductors/beams 61 a and 61 b is their generallyrectangular or “blade-like” cross-sectional shape which providespreferential (anisometric) bending, allowing the tip to move in adirection along the Z-axis. The blade-like shapes of conductors 61 a and61 b are also contributors to a relatively high lateral-frequencycharacteristic for flexure 60. Still another interesting geometricfeature of conductors 61 a and 61 b is their symmetrical organizationabout plane W which bisects flexure 60 along its length. Between theiropposite sets of ends, these conductors are also referred to assubstructure spans.

A second important load-bearing structure embodied in thetransducer/flexure of FIG. 1A, as briefly mentioned earlier, is thetransducer itself (the embedded pole structure and coil and conductorstructure mentioned earlier) located at the distal tip of flexure 60.Unlike flexures/transducers in the prior art, such as transducers joinedto massive load-bearing, sliders, in which the transducer carriesessentially none of the deflected beam load, the transducer integratedin the distal tip of flexure 60 directly contacts disk 64 and carries100% of the cantilever load—i.e., directly through the embedded pole,coil, and conductor structure. The uses of load-bearing conductors and aload-bearing transducer in a transducer/flexure device, provide examplesof a major theme of the present invention, namely, to designmulti-functional (i.e., merged-functionality) components so thatstructures, such as conductors and transducers, which traditionally havehad no mechanical function in prior art devices, become “mechanicalactivists” in the present invention, in addition to playing theirtraditional roles of conducting electrical signals and handling magneticflux.

A related micro-flexure structure 70 with load-bearing conductors, orconductor elements, and a proximal hinge, or hinge region, isillustrated in FIG. 2. Micro-flexure 70 includes two, relatively flat,blade-like conductors (continuum structure) 72 and 74. Conductors 72 and74, which form a common conductive layer, are insulated from each otherby space 75. Conductors 72 and 74, collectively, have a tapered shape,and are widest at proximal (mounting) end 76 and narrowest at distal(free, disk-confronting, transducer-carrying) end 78. End 76 is alsoreferred to herein as a base region. A proximal stiffener layer, orstiffener, 80 overlays the proximal ends 76 of conductors 72 and 74.Stiffener 80 has a hole 82 centrally located above a hole 84 defined byconductors 72 and 74. Holes 82 and 84 are used for alignment of thesuspension to a mounting surface in a disk-drive system. A rectangularwindow 86 in stiffener 80 provides access to the top sides of conductors72 and 74 for electrical bonding. Distal and proximal bonding regions ofconductors 72 and 74 are preferably gold plated. A second stiffener 88extends from a “hinge region” 89 near the proximal end of the flexure,to the distal end of the flexure. Hinge region 89, defined by the gapbetween stiffeners 80 and 88, is shown more completely in FIG. 3A, FIG.4 and FIG. 6. The structural regions located longitudinally on oppositesides of the gap are also referred to herein as arms. Four windows 90 instiffener 88 provide access to the conductors for heating them in theprocess of connecting a transducer chip 92 to the bottom side ofconductors 72 and 74. Chip 92 contains, for example, a probe-typeread/write transducer (not illustrated), the probe in which extendstoward the disk's recording surface through a single, projecting contact(wear) pad, or projection, 97 (see FIG. 3B).

A top view of flexure 70 is illustrated in FIG. 3A. Conductors 72 and 74are seen in hinge region 89 where they are separated by a gap 75. Inaddition to being tapered from hinge region 89 to the distal end offlexure 70, lateral edges 94 a and 94 b in the flexure are slightlyconcave—a design feature which has been found to yield improved (higher)torsional frequency characteristics.

Hinge region 89 of flexure 70 has the following preferredspecifications. Conductors 72 and 74 and stiffeners 80 and 88 aretype-302 (or type-304) stainless steel. The thickness of the hingematerial, i.e., conductors 72 and 74, is 0.5-mils. (1mil.=1/1000-of-an-inch). The length of the hinge is 24-mils. Thesedimensions were selected for the purpose of maintaining a springconstant of approximately 2.5-mgs.-per-mil. Stiffeners 80 and 88 are1-mil. thick. Thus, most of the bending which occurs when the flexure isdeflected, occurs in hinge region 89.

The hinge design just described provides a number of important benefits.First, a lower angular constant is achieved relative to a non-hingeddesign. Optimal angular constant for a simple cantilever, such as theone illustrated in FIGS. 2 and 3A, is achieved when all the bendingoccurs at the base (i.e., a perfect hinge). In the flexure shown inFIGS. 2 and 3A, most of the bending occurs in the base 7% of the beam.This results in an angular constant of approximately 0.19°-per-mil. ofdeflection. Second, the hinge provides damping capability. Since most ofthe flexure is rigid, constrained-layer (electrically insulating)damping material, as illustrated in FIGS. 5A, 5B and 5C (discussed indetail below), can be added to the stiffened region without affectingthe spring constant. The damping material can be positioned between theconductor and stiffener layers, and/or another set of damping andconstraining layers can be added above or below the flexure if necessaryto attenuate vibrational amplitudes. Third, the hinge provides improveddrive tolerances. If a pre-bend is added to the hinge area of theflexure, the suspension can operate essentially flat—thus requiring lessmounting space. This allows very close disk-to-disk spacing. Structures,considerations and benefits relating to the concepts of pre-bentflexures and disk-to-disk spacing will be more fully developed below.

The trapezoidal/concave edge shape of the flexure, overall beamthickness, and 350-mil. free beam length provide the followingadvantages. First, the shape provides good lateral stiffness. Lateralstiffness increases as the cube of width. High lateral stiffness isdesirable for minimizing lateral vibrational movement. Second, bytapering the width at the tip, high lateral frequencies are achievedwhich are desirable for servo stability. Third, the “bugle” orconcave-edge shape was found to have the highest torsional frequency oftrapezoidal-like shapes. High torsional frequency is desirable for servostability because there can be a significant off-track motion associatedwith the torsional mode. Fourth, the design has been found to avoidundesirable modal interactions. We have discovered that certain normalmodes of vibration interact with others, causing high vibrationalamplitudes. Such interaction is caused by frictional changes at thetransducer/disk interface with contact pad angle changes. Accordingly,the following situations should be avoided: (1) lateral frequency 1×, 2×or 3× the torsional frequency, and (2) torsional or lateral frequency of1× or 2× any first or second bending frequency.

FIG. 3B is a side view of the distal end of flexure 70, illustrating themounting of transducer chip 92 on flexure 70. Stiffener 88 is separatedfrom conductor 72 by an adhesive (bonding) layer 95. Solder structures,plus adhesive and/or conductive epoxy structures in some cases, such asthe solder structures shown at 96 a and 96 b, electrically andmechanically connect conductor 72 to chip 92. Full mechanical load istransmitted through these connections. Single pad 97 is preferably madeof amorphous diamond-like carbon (DLC), and is positioned on the bottomside (in FIG. 3B) of chip 92, near the center of its trailing edge, asshown in FIG. 3C. When transducer/flexure 70 is in its operating mode,pad 97 contacts the uppermost surface of disk (medium) 98. Thesingle-pad configuration which is employed in transducer/flexure 70 andillustrated in FIGS. 3B and 3C is characteristic of the flexures shownin FIGS. 1-9, which do not include gimbals. When a single pad isemployed in a non-gimbaled flexure, facets are polished around the padto provide full transducer signal through a range of static mountingtolerance. Other pad configurations and considerations are discussedbelow. Similar to the integrated transducer/flexure structure shown inFIGS. 1A and 1B, transducer chip 92, as shown in FIG. 3B, bears theentire cantilever load of the deflected beam. Thus, the need for aseparate load-bearing structure is avoided.

In the configuration shown in FIG. 3B, chip 92 contains transducer polestructure and coupled coil structure organized and distributed in thefollowing fashion. The read/write working portion of the pole structureextends within pad 97 to the bottom (in FIG. 3) disk-contacting face ofthe pad. The coupled coil structure occupies the generally horizontal(in FIG. 3) plane of the main body of the chip.

Shifting focus briefly onto the modification shown in FIG. 3D, here chip92 contains pole structure and coil structure organized and distributedin a somewhat different manner. Specifically, here, both of thesestructures occupy a plane which extends generally normal to the longaxis of flexure 70. This planar region is indicated generally at 99.Here too the read/write working portion of the pole structure extendswithin pad 97 to the bottom face of the pad. This organization isreferred to as a “pin head” type arrangement.

The FIG. 3D embodiment suggests the possibility of creating yet anotherkind of transducer chip which is fully planar, and intended for suitablemounting at the end of a beam/flexure, in a disposition with its plane,including the plane of the body of the chip, normal to the long axis ofthe beam/flexure. Such a situation is specifically illustrated anddescribed in a portion of this specification set forth below. In allcases the transducer is load-bearing.

The performance or flexibility of the hinge region can be modified ortuned by, for example, altering the dimensions of the conductors in thehinge region, or by changing the width of the gap between stiffeners, asillustrated in FIG. 4. Here, for example, an illustrated hinge 100includes conductor portions 102 and 104 flanked by stiffeners 105 and106. Flexibility of conductor portions 102 and 104 in the hinge regioncan be altered or tuned by changing the gap width. For example, if thehinge gap edge is relocated to line 109, then hinge flexibility isincreased. Similarly, other changes in conductor geometry or materialcomposition provide different ways of tuning the hinge.

FIG. 5A shows a cross section of flexure 70 as illustrated in FIG. 3A.Conductors 72 and 74 are separated by air gap 75, and are bound tostiffener 88 via adhesive layer 95 (a resin). Stiffener 88 and layer 95collaboratively form joinder structure for the conductors. Importantly,resin 95 functions to insulate conductors 72 and 74 electrically fromstiffener 88. Stiffening and/or vibrational damping can be enhanced byselecting an appropriate type, amount and application of the adhesiveresin. Adhesive layer 95 is preferably 1.0-mil. thick. Adhesive resinswhich have been used to bond conductor and stiffening layers in laminantflexures of the present invention include epoxies, acrylics andpolyimides in both liquid and sheet forms. For example a liquid epoxyresin available from Bondline, referred to as 6555™, can be used in thepresent invention. An epoxy resin in sheet form is available from AITechnology, referred to as TK7755™. An acrylic resin which can be usedin the present invention is sold by DuPont under the trademark Pyralux™.A polyimide resin sold by DuPont under the name Kapton™ is anothersuitable alternative. Other good adhesive layer materials have beenidentified by Hutchinson Technology Incorporated which is located inHutchinson, Minn.

FIGS. 5B and 5C illustrate another feature of the invention which may beemployed to provide vibrational damping in addition to any dampingeffect which may be achieved by resin layer 95 which is sandwichedbetween conducting and stiffening layers. In FIG. 5B, a damping layer112 is continuously sandwiched between stiffener 88 and a constraininglayer 114, which, for example, may be stainless steel. Although it ispossible to use a damping layer without a constraining layer, betterresults are obtained when the damping material is sandwiched betweenmore rigid solids. This is because the damping effect relies on theabsorption of shear energy in the damping layer. The amount of shearenergy produced from vibrational motion of the flexure, and subsequentlyabsorbed by the damping layer, is increased by using a constraininglayer. FIG. 5C is the same as FIG. 5B except that it shows that dampinglayer 116 may be applied on the bottom side of the flexure, where it issandwiched between conductors 72 and 74, and constraining layer 118. Asshown in FIG. 5C, damping layer 116 spans gap 75 between conductors 72and 74. However, it is also possible for damping layer 116 to be omittedin the region of gap 75, analogous to adhesive layer 95. Conversely, itis possible for adhesive layer 95 continuously to span gap 75 betweenconductors 72 and 74. A material known as ISD110™ or ISD112™, availablefrom 3M Corporation, is suitable for damping layers 112 and 116.

FIG. 6 shows a side view of hinge region 89 of flexure 70. Proximalstiffener 80 and distal stiffener 88 flank hinge region 89. Resin layer95 extends continuously in the region where stiffeners 80 and 88 overlayconductors 72 and 74. Further considering some of the features whichcharacterize hinge or hinge region 89, within the elongate body offlexure 70, the hinge region can be thought of as having longitudinalboundaries which are indicated in FIG. 6 by dash-dot lines 89 a, 89 b.The conductor material which makes up hinge region 89 is homogeneous(outside of these two longitudinal boundaries) only with material whichlies bounded between common (shared) spaced facial planes whichintersect the regions of boundaries 89 a, 89 b. These two common facialplanes are illustrated by dash-dot lines 73 a, 73 b in FIG. 6. Anotherway of viewing this is that the material in hinge region 89 ishomogeneous, beyond boundaries 89 a, 89 b, only with extensions of theconductor material itself which makes up the hinge region.

FIG. 7 schematically illustrates change in adhesive conformation due toflexure deflection. By selecting an appropriate type of resin, and bycontrolling the amount used, it is possible to vary the degree ofstiffening obtained in the stiffened region. The type and amount ofresin 95 can also be selected to provide an advantageous vibrationaldamping effect. Resins typically exhibit varying degrees of elasticity.In FIG. 7, rectangular resin section 132 is stretched into trapezoidalresin section 134 when the flexure is bent. A greater degree ofstiffening is therefore achieved by selecting a resin which isrelatively unyielding or resistant to stretching.

FIGS. 8 and 9 illustrate views of a modified flexure, which in manyrespects is the same as the flexure shown in FIGS. 2 and 3A. Animportant difference, however, is that in the flexure shown in FIGS. 8and 9, four conductors are provided in the conductive layer. It issometimes necessary to provide more than two conductors to the distalend of the flexure. For example, in transducer/flexure structures whichinclude a magnetoresistive read substructure, at least four conductorsare required. FIGS. 8 and 9 illustrate that the concept of the presentinvention, characterized by multiple load-bearing conductors, mayencompass designs which include many more than two conductors, eventhough most of the flexures specifically described in this applicationinclude only two load-bearing conductors.

In FIG. 8, a flexure 140 includes a stiffener 142 and a stiffener 144overlaying load-bearing conductors 146, 148, 150 and 152. As in thepreviously described design, although not shown in FIG. 8, thestiffeners are bound to the conductors by an insulative adhesive resin.Transducer chip 154 is directly bonded to the bottom side of conductors146, 148, 150 and 152, substantially as shown in FIG. 3B. A single wearpad is provided on the bottom side of chip 154 near the center of itstrailing edge. FIG. 9 shows the outline of the conductors in dashedlines. Note that in this structure, the conductors are distributedsymmetrically with respect to an imaginary plane which bisects theflexure along its length.

Turning attention now away from non-gimbaled structures made inaccordance with the teachings of this invention toward gimbaledstructures, it is important to note that gimbaled-type structures arefundamentally different from the flexure/transducer structures whichhave been described so far above. They are different in that gimbalmechanism allows the transducer chip ranges of pitch and roll motionindependent from the supporting flexure body. Gimbaling movement of atransducer chip has been recognized as an extremely important mechanicalfeature with respect both to flying structures and to contact-capablestructures. In the non-gimbaled flexures described above, the conductorshave been characterized as “load-bearing” structures because of therelative size and configuration in a proximal hinge region andthroughout the body or length of the flexure. In the descriptions whichnow immediately follow, gimbal flexures are described in which theconductors fulfill additional mechanical load-bearing and articulatingfunctions, such as hinge and torsional flexibility for adistally-located gimbal which permits pitch and roll movement of thetransducer chip relative to the flexure body. These gimbaledconfigurations are illustrated collectively in FIGS. 13-30, inclusive,and in each of the designs therein illustrated, the conductorscontribute functionally in at least three important ways: (1) to conductelectrical signals between a transducer and external circuitry; (2) tobear all or a portion of the deflected cantilever load, at least at somepoint along the length of the flexure; and (3) to provide a gimbalplatform (a transducer-carrying platform) for mounting a transducerchip. Accordingly, the embodiments that are shown in the collection offigures just mentioned are referred to as “conductor gimbalingflexures”.

A further matter to note is that in all of the flexure/transducerstructures which are described and discussed in this specification,there exists, fundamentally, a three-layer flexure structure to whichthere is attached or joined, in various ways, a transducer chip. Thethree layers in each flexure structure include a conductor layer, anadhesive layer, and a stiffener layer, and in each of these layers, andin the different embodiments, the specific configurations of thecomponents in the layer are somewhat different. Relying on the fact thatall now-to-be-described flexure/transducer assemblies have, in manyrespects, similar organizational characteristics, descriptions of theseembodiments will be presented in a more conversational flow ofstructural and functional qualities, rather than with a mechanisticlisting of parts followed by a functional description, and with aneffort to focus principally, and inter alia, on key differences thatdifferentiate the different embodiments.

Thus, and turning attention first of all now to FIGS. 10, 11, 12A, 12Band 12C, here there is illustrated an embodiment of the invention whichemploys what is referred to as a “load-button” gimbal. This embodimentclosely resembles a head/flexure design previously disclosed and claimedin co-pending U.S. application Ser. No. 07/783,619. Here atransducer/flexure 160 is principally supported by load-bearingconductors 162 and 164. At the distal end of conductors 162 and 164 arearticulator “ribbons” 166 a and 166 b on which a transducer chip 168 ismounted. A load button 170 is provided on the top side of chip 168around which rocking, inclinational movement of the chip is allowed. Itis important to note, however, that the load button could also beprovided on the bottom side of stiffener 180 for example, by creating adownwardly protruding dimple. The height of load button 170 isapproximately equal to the thickness (0.5-mils) of conductors 162 and164 plus the thickness of adhesive layers 174 and 176. Adhesive layers174 and 176 facilitate lamination of stiffeners 178 and 180 on top ofconductors 162 and 164. FIG. 11 shows assembled flexure 160 withdetached transducer chip 168. FIG. 12A shows the top view of assembledflexure 160.

FIG. 12B illustrates the mounting configuration of transducer 168 onflexure 160. In the region of flexure 160 where transducer 168 isattached, stiffener 180 is separated from conductor ribbon 166 b by air.As shown in FIG. 10, adhesive layer 176 only extends distally to thepoint where ribbons 166 a and 166 b begin. Transducer 168 is bonded bysolder structure 188 a and 188 b to conductor ribbon 166 b. The bottomside of transducer 168 has three wear pads 190 a, 190 b and 190 c (seeparticularly FIG. 12C) which contact the disk surface in a triangular(tripodic) pattern when the transducer is operating. Ideally, sufficientload is applied to flexure to maintain contact between each of the padsand the disk surface at all times.

In FIG. 13, flexure 200 includes conductors 202 and 204 which are spacedapart from each other and extend along the entire length of flexure 200.A gimbal structure or region 206 of the conductors is located near thedistal ends of the conductors. Each conductor contributes one of a pairof parallel platforms (or articulated portions) 208 a and 208 b whichare located centrally within a cut-out gimbal region and servecollectively as a mounting platform for transducer chip 210. Thismounting platform is located adjacent what is also referred to herein asthe transducer unit receiving end of flexure 200. Platforms 208 a, 208 bare also referred to as paddle portions. Stiffeners 212 and 214 arelaminated, via adhesive as previously described, onto the tops ofconductors 202 and 204 on opposite sides of gap 213 which defines ahinge region. The stiffeners rigidify portions of conductors 202 and 204outside of hinge region 213. Additionally, the stiffeners' continuityfrom side-to-side provides structural compliance between the twoload-bearing conductors 202 and 204. In gimbal region 218 toward thedistal end of stiffener 214, two additional stiffeners 220 and 222 arelaminated above the gimbal region 206 of conductors 202 and 204.Stiffeners 220 and 222 serve to coordinate corresponding conductorregions and to isolate mechanical articulating conductors, i.e.,conductive torsional beams, which will be shown and discussed in moredetail below.

FIG. 14 shows a magnified top view of gimbal region 206 of conductors202 and 204. Conductors 202 and 204 are distinctively shaded to assistthe viewer in understanding the mechanical relationship and electricalisolation of the conductors. Platforms 208 a and 208 b are coordinatedand jointly stiffened on the top side by stiffener 222. On the bottomside of platforms 208 a and 208 b, transducer chip 210 is attached. Itis apparent that platforms 208 a and 208 b also function as electricallydistinct leads to transducer 210. Torsional beams (articulators, units,elements) 230 a and 230 b allow platforms 208 a and 208 b a limitedrange of pitch flexibility. Similarly, torsional beams (articulators,units, elements) 232 a and 232 b allow platforms 208 a and 208 b alimited range of roll flexibility. Beams 230 a 230 b, 232 a, 232 b,collectively, constitute articulator structure which is referred toherein as being characterized by mechanical and electrical homogeneity—i.e., merged functionality. The gimbaling motion permitted by thetorsional beams makes possible accommodation of angular or topographicirregularities on the surface of a rigid medium. Although the surface ofa medium is ideally flat, in reality, irregularities due to, forexample, micro-roughness, polishing/texturing scratches, disk wavinessand/or “cupping”, non-parallelism of the spindle and actuator axes, andnon-squareness of either of these axes and the disk surface, areinherently present to some degree. The torsional beams also permit thehead/flexure to accommodate static mounting tolerances.

FIG. 15A shows a top view of the flexure shown in FIG. 13, afterassembly. In FIG. 15A portions of conductors 202 and 204 can be seen inhinge region 244 and through window 242 which allows electrical bondingthrough the top side of flexure 200. Stiffener 212 also has hole 240concentrically located above conductor hole 241. Holes 240 and 241 areused for positioning the suspension on a mounting surface. Near thedistal end of flexure 200, gaps between stiffeners 220 and 222 defineflexible torsional beam portions of conductors 202 and 204.

An important feature of all the gimbaled flexures described in thisapplication is the configuration of pads (the three contact pads)located on the bottom side of the transducer chip for contacting thesurface of the recording medium during read/write operation. Unlike thenon-gimbaled flexures, a fundamental objective in the gimbaled designsis to maintain a parallel relationship (zero-angle-of-attack) betweenthe plane of the transducer chip and the surface of the recordingmedium. For this purpose, a load force is applied, via the deflectedflexure, urging the transducer chip into load-bearing contact with thedisk's surface. Multiple pad contact points on the bottom of thetransducer chip define a plane of interfacial contact between the chipand the disk. Ideally, torsional beams and/or hinges, load buttons, etc.permit the interfacial contact plane between the disk and the pads toremain intact, despite mounting tolerances and disk surface aberrations,throughout normal read/write system operation. The most common padconfiguration employed in the gimbaling flexures of the presentinvention, consists of a triangular arrangement of three pads, onelocated in the center of the trailing (or distal) edge of the transducerchip, and the other two pads being located at opposite front corners ofthe chip. The pole, which is contained typically in the trailing pad, ispreferably in constant contact with the surface of the media for themost high-level read/write performance. While this is a typicalarrangement, a reverse kind of arrangement is possible, and may offercertain performance advantages in selected applications. Moreparticularly, the central, pole-containing pad could be located adjacentthe leading edge of the chip. With this type of arrangement, relativemotion between the chip and disk tends to drive the leading-edgepole-containing pad into even more intimate working confrontation to therecording surface in a medium. Further, it is possible that polestructures might be provided in two, or in all three, of the pads.

Maximum stability is achieved when the pads are located as far apart aspossible, consistent with chip size and disk flatness constraints.During pad-disk contact, the pads may be perturbed in the Z direction byhitting pits or asperities in the surface. When this occurs, thedownward load must be great enough to restore contact quickly betweenthe pads and the disk. Pad size and shape is not critical except that itis desirable to have the pad that contains the pole be as small aspossible to minimize spacing loss, inasmuch as the actual contact pointon the pad varies due to disk waviness. For wear reasons, it may bedesirable to have larger pads which can sustain larger removed wearvolumes. Pads that become too large may create an air-bearing surfacethat causes a contact-intended transducer to fly rather than to slide.In addition, larger pads may exhibit higher adhesion forces, andconsequently additional friction and stiction during operation. Roundpads may be desirable so that debris will not collect on a flat leadingedge, as has been observed in some cases on square or rectangular pads.

FIGS. 15B and 15C illustrate the pad configuration used on the bottomside of transducer chip 210. Stiffener 214 is laminated, via adhesive247, to conductor 202. Conductor 202 is electrically and mechanicallyattached to the top side of transducer chip 210 by load-bearing solderstructures 248 a and 248 b. The chip may also be attached to theconductors by processes employing brazing or conductive epoxy materials.As shown in FIG. 15C, pads 250 a, 250 b and 250 c are arranged in amaximally separated triangular configuration on the bottom side oftransducer chip 210.

A large number of possible pad configurations may be employed in thegimbal structures of the present invention. It is generally preferred touse not more than three pads because four or more contact points createthe possibility for rocking of the chip on the disk surface. It ispossible for all three pads to be directly connected to the transducerchip, or alternatively, as described in detail below, one or more of thepads may be located on other parts of the flexure which articulaterelative to the transducer-carrying portion of the flexure. In most ofthe gimbal structures described in this application, the pole-containingpad is located on the trailing edge of the chip body. However, as shownby arrow 250 d, in FIG. 15C, and as was mentioned earlier, it ispossible, and sometimes preferable, to position the pole-containing padon the leading edge of the chip (by rotating the chip 180°, or byreversing the direction of disk rotation). We have discovered that thepad(s) which is positioned on the leading edge of the chip experiences asignificant amount of friction with the disk surface, causing anunloading affect on the pad or pads located on the trailing edge of thechip. This phenomenon must be taken into account when deciding where toposition pitch articulators in a gimbal. Further, we have found thatelectromagnetic signal performance can vary significantly depending onwhether the pole-containing pad is on the leading edge or on thetrailing edge of the chip body. In general, we have observed asignificant increase in signal magnitude when the pole is positioned onthe leading edge (instead of on the trailing edge) of the chip.

In a tri-pad arrangement of the type shown in FIG. 15C, where thetransducer chip is mounted on a gimbal permitting all three pads tocontact the surface of the medium continuously during normal operation,the transducer chip remains in a substantially parallel orientation,i.e., at a zero-angle-of-attack, relative to the surface of a disk. Thisfeature of the disclosed gimbal structures, represents a major departurefrom prior transducers/flexures which exhibit substantialangles-of-attack relative to a disk's surface. Positioning thetransducer chip to operate at a zero-angle-of-attack relative to thedisk surface provides the capability of employing a transducer designwhich, due to a particular coil structure, requires the main polestructure to be located inward from the transducer chip's trailing edge.

For example, as illustrated in FIGS. 15D and 15E, it is sometimesdesirable to locate a pad containing the main pole, inward from thetrailing edge of the chip. Flexure/transducer 251 is supported by beam252. Transducer chip, or chip body, 253, which is generally quite thinand planar, is mounted on the bottom side of beam 252. Projectingtri-pads 254 a, 254 b and 254 c are located on the bottom side of body253, defining a plane of interfacial contact between the transducer andthe disk's surface 256. Inductively coupled to the pole structure is agenerally planarly distributed coil, or coil structure, which lies inthe plane of chip body 253 in a coil region 255 generally designated bydashed lines in body 253. As shown, it is sometimes desirable to employa coil design which extends forward and backward from pole 254 a alongthe Y axis. In such a design, it is necessary to position thepole-containing pad inward from the trailing edge of the chip. Thisdesign goal is problematic, i.e., sometimes impossible, in aflexure/transducer which positions the chip with a significantangle-of-attack relative to a disk's surface. This is because, as thepole is moved inward from the trailing edge of a chip body, which isoriented with a significant angle-of-attack, it becomes impossible forthe pole to contact the disk. The distance between the pole and the diskbecomes greater and greater as the distance between the pole and thetrailing edge increases. Accordingly, the flexibility for implementingalternative pole and coil designs in transducers which operate at asignificant angle-of-attack is quite limited. It is important to notethat the positioning of pitch and roll articulators in a given gimbalconfiguration is primarily determined by the locations of the contactpads. For example, as the pole-containing pad is moved inward from thetrailing edge of the chip body, pitch articulators in the gimbal mustalso be moved in the same direction in order to maintain the desiredgimbal performance and load allocation among the pads.

In contrast, by providing a flexure/gimbal structure, which is capableof supporting a transducer chip in parallel orientation(zero-angle-of-attack) relative to a disk's surface, a great improvementin transducer design flexibility is made possible. In the flexure/gimbalstructures of the present invention, the pole-containing pad may belocated practically anywhere on the working side or surface of the chipwithout altering the operable spacing (or contact relationship) betweenthe pole and the disk surface. The entire planar body of the transducerchip is available for containing coupled pole structure and coilstructure.

FIG. 16 is a thin-layer section including the pitch-accommodatingtorsional beams of the flexure shown in FIG. 15. The structures oftorsional beams 230 a and 230 b are analogous to conductor hinge 89 inFIG. 6.

FIGS. 17A and 17B illustrate a portion of a conductor gimbaling flexurewhich in all respects is the same as the flexure shown in FIGS. 13-16,except that an additional damping layer is added. In FIG. 17A, dampinglayer 260 covers substantially the entire gimbal. Damping layer 260 maybe, for example, an elastomer available from 3M under the trademarkISD110™ or ISD112™. The material is preferably diluted with ethylacetateto 10% (V/V) of its original concentration, and then applied to the topof the flexure in the gimbal region as shown in FIG. 17A. Use of such amembrane layer results in significant vibrational damping. It isbelieved that shear energy is absorbed by the membrane, particularly inregions of the gimbal where the maximum amount of vibrational movementis expected to occur. A thin membrane can be employed for this purposewithout significantly stiffening the pitch and roll motions otherwisepermitted by the gimbal. However, to minimize further any stiffeningeffect of the membrane on the gimbal, and as is shown in FIG. 17B, amodified damping membrane configuration includes four discretemembranes, or membrane patches, 262 a, 262 b, 264 a and 264 b, each ofwhich bridges two separate conductor portions in an area where thegreatest degree of relative movement between the portions is expected tooccur. It is preferable to select a damping material which exhibits arelatively high degree of elasticity under static conditions, and a highdegree of stiffness when subjected to a high-frequency condition.

Another desirable way of employing a damping membrane, such as the onesillustrated in FIGS. 17A and 17B, is to position the damping membranebetween either stiffener and conductor, or the flexure and an additionalconstraining layer. Ideally, the adhesive layer, which is alreadyrequired in each of the laminant flexures described herein, and whichcan furnish damping action, may extend continuously through the gimbalregion. The adhesive layer may extend through all of the gaps betweenstiffeners 214, 220 and 222 in the gimbal region. Alternatively, and inorder to minimize any stiffening effect of the membrane on the gimbal,the adhesive layer may bridge gaps between stiffeners only in discreteregions where maximum movement between the stiffeners is expected tooccur, similar to the configuration shown in FIG. 17B.

FIG. 18 shows another embodiment of a gimbaled transducer/flexure whichemploys a membrane interconnecting a flexure body and a transducer chip.In the structure shown in FIG. 18, the membrane functions primarily as agimbaling structure and possibly also a damping layer.Transducer/flexure 270 includes a flexure frame portion 271 from whichtrace conductors 272 a and 272 b extend to transducer chip 273. Threecontact pads 274 a, 274 b and 274 c (dashed lines) are located on thebottom (working) side of transducer chip 273. The transducer pole (notshown) is preferably located in contact pad 274 a. In this design, traceconductors 272 a and 272 b are downsized (compared to previouslydescribed conductors) and shaped (folded or curved) so as to make theconductors insignificant structural contributors in thetransducer/gimbal region. Elastomeric membrane 276 spans the gap regionbetween flexure frame portion 271 and transducer chip 273. As alreadydescribed with reference to FIGS. 17A and 17B, a membraneinterconnecting a flexure frame and a transducer chip can be employedadvantageously for the purpose of damping vibrations. However, theprimary function performed by membrane 276 is to bear the cantileverload while permitting ranges of pitch and roll movement of transducerchip 273. Membrane layer 276 is the only significant load-bearingconnection between frame portion 271 and transducer chip 273. Byselecting the appropriate type, thickness and configuration, membrane276 may function as a gimbal structure to allow pitch and roll movementof transducer chip 273 independent from flexure frame portion 271, whilepossibly also damping vibrations. Membrane 276 is preferably sandwichedbetween flexure frame subportions and/or conductors.

FIGS. 19A, 19B and 20 illustrate a flexure which is similar to the oneillustrated in FIGS. 13-16 except for several important differences. Asshown in FIG. 19A, flexure 280 has two hinges 281 and 282. Hinge 281 ischaracterized by a cut-out window in stiffener 283 near its proximal endexposing relatively thin conductors 284 and 286. The outlines ofconductors 284 and 286 underneath the stiffeners are shown in dashedlines. It is apparent that, although the reduced dimensions ofconductors 284 and 286 in the proximal hinge region (relative to thedimensions of previously described conductors) diminishes theload-bearing function of the conductors in that region, in theintermediate region of the flexure the conductors are wider, andtherefore carry a significant portion of the load. The configuration ofmodified hinge 280 results in a higher spring constant for accommodatinghigher loads in comparison to the loads carried by previously describedflexures.

The configuration of hinge 282 near the distal end of the flexure issimilar to previously described hinges in that conductors 284 and 286are the sole load-bearing structures in that region. Gimbal 288 allowspitch and roll movement of stiffened transducer-carrying platform 289.Similar to the gimbal shown in FIGS. 13-15, gimbal 288 employs torsionalbeams 290 a and 290 b to allow roll movement of platform 289 independentfrom the body of flexure 280. Pitch movement is facilitated by hinges(articulators, units, elements) 292 a and 292 b which are rearwardlydisplaced from the center of the platform in order to equalize loaddistribution among the three medium-contacting pads (not shown). The useof hinges instead of torsional beams provides the important advantage ofincreased longitudinal and yaw stiffness. Another advantage of usinghinges to provide pitch movement instead of torsional beams is thatoverall width of the flexure in the gimbal region can be reduced. Thepitch-permissive hinges also provide a platform for dispensing adhesive.The configuration of conductors 284 and 286 in gimbal region 288 offlexure 280 is shown in FIG. 19B. Conductor 286 enters the gimbalmechanism through roll-permissive torsional beam 290 a, and enters thetransducer-carrying region through pitch-permissive conductor/hinge 292a to end in transducer-carrying semi-platform 293 a. Similarly,conductor 284 enters the gimbal mechanism through roll-permissivetorsional beam 290 b, and enters the transducer-carrying region throughpitch-permissive conductor hinge 292 b to end in transducer-carryingsemi-platform 293 b.

FIG. 20 shows a side view of flexure 280 operating on disk 295. Most ofthe bending which results from deflection of the flexure occurs inhinges 281 and 282. Gimbal 288 mounts and supports transducer chip 296.A “tri-pad” configuration (only two pads 297 a and 297 b are shown), aspreviously described, exists for maintaining an interfacial contactplane between chip 296 and the surface of disk 295.

Flexure 300, as shown in FIG. 21, is the same as flexure 280 shown inFIG. 19, except that the dimensions of conductors 302 and 304 in regionI are modified, and that flexure 300 is pre-bent in proximal hingeregion 306 (FIG. 22A). This prebend exists along an axis 306 a (see FIG.21) which defines a preferential bending axis for flexure 360.

Stiffener layers 301 a, 301 b, 301 c and 301 d are laminated on top ofconductors 302 and 304. The lateral dimensions of conductors 302 and 304in region I are shown in dashed lines because the conductors are coveredby stiffener 301 a. The reduction of conductor width in region I canresult in a significant reduction in capacitance levels.

The conductors can be made of different materials. However, a number offactors must be considered when selecting an appropriate conductormaterial. In addition to being able to conduct electricity, theconductor material must exhibit appropriate physical/mechanicalproperties within the geometric and dimensional limitations whichdictate the operation and overall size of the flexure. When theconductors function as the only load-bearing components of the proximalhinge, as in previously described designs, it is preferable to usematerials, such as stainless steel, which have a relatively high elastic(Young's) modulus resulting in higher modal frequencies, and hightensible strength which can therefore support higher loads. However, inflexures such as the ones shown in FIGS. 19-22B, where the conductorsare relatively insignificant load-bearing components in the proximalhinge, beryllium copper is a suitable choice of material. With someconductor materials, such as stainless steel, it is preferable togold-plate the entire surface for at least two reasons. First,gold-plating in the bonding regions facilitates a solder connection.Second, gold-plating the entire stainless steel beam reduces resistance.When beryllium copper is used as the conductor material, it is onlynecessary to gold-plate the bonding regions.

FIG. 22A shows flexure 300 in its unloaded position U (solid lines) andin its loaded position L (dash-dot lines) relative to disk 310. Bypre-bending flexure 300 in hinge region 306 (on axis 306 a), flexuremount 312 can be parallel to the disk surface, thereby, minimizingdisk-to-disk spacing.

FIG. 22B illustrates a modification of flexure 300 which involves theuse of gimbal-motion-limiting guides, or “bumpers”, for the purpose ofavoiding extreme, potentially catastrophic movement of gimbal parts outof the plane of flexure 300 in the case of a relatively high-shocksituation. Read/write systems are sometimes subjected to high-shockforces, for example, when a system is dropped or moved abruptly. In thissituation, gimbal parts which are connected by relatively small hingesor torsional beams, may be moved, bent or broken permanently away fromtheir operable positions. Accordingly, the modification of flexure 300shown in FIG. 22B, provides motion-limiting bumpers for preventingextreme movement of the gimbal parts with respect to the flexure bodyand to each other. In FIG. 22B, flexure 300 includes conductors 302 and304, the configuration of which has already been discussed referring toFIGS. 19A through 22A. Stiffeners 312 a, 312 b, 312 c and 312 d arelaminated on top of conductors 302 and 304. Stiffeners 312 h, 312 c and312 d differ from previously described stiffeners in that they includetabs which extend over air gaps between gimbal parts. These tabspartially cover (but do not touch) exposed conductor regions in anadjacent gimbal part. For example, tabs 314 a, 314 b, 314 c and 314 dextend over conductor edge regions of gimbal part 317. Bumpers 314 a,314 b, 314 c and 314 d significantly limit the extent to which gimbalpart 317 can move above the plane of flexure 300 in a high-shocksituation, while still allowing the desired range of roll torsionalmovement of the transducer chip independent from the body of flexure300. Similarly, tabs 316 a and 316 b are extensions of stiffener 312 c,protruding over conductor edge regions of transducer-carrying platform318. Bumpers, or tabs, 316 a and 316 b prevent extreme movement ofplatform 318 above the plane of gimbal part 317 or the body of flexure300, while still allowing the desired degree of pitch movement ofplatform 318 independent from the rest of flexure 300. Extreme movementof the gimbal parts below the body of flexure 300, can also be preventedby outwardly extending tabs 319 a, 319 b, 319 c and 319 d. Each of tabs319 a, 319 b, 319 c 319 d extend over a gap separating gimbal part 317from the body of flexure 300, and over an exposed conductor regiondefined by corresponding cut-outs in stiffener 312 b. It is apparent(although not shown) that similar outwardly extending tabs could beemployed to limit extreme movement of platform 318 below the plane ofgimbal part 317.

FIGS. 23-25 illustrate modified conductor gimbal configurationsemploying conducting articulators, namely, torsional beams, to allowlimited ranges of pitch and roll movement of a transducer platformindependent from a flexure body. Each of the gimbaling conductorstructures shown in FIGS. 23-25 can be implemented, with correspondingstiffeners, in flexures such as the ones shown in FIGS. 13-22B.Specifically, the gimbaling conductor structure shown in FIG. 14 couldbe replaced (along with appropriately modified stiffeners) with any oneof the structures shown in FIGS. 23-25.

In FIG. 23, gimbaling conductor configuration 320 is similar to the oneshown in FIG. 14, except that pitch-permissive torsional beams 322 a and322 b are located laterally and externally from roll-permissivetorsional beams 324 a and 324 b. In contrast to the FIG. 14configuration, where pitch-permissive torsional beams 230 a and 230 bconnect directly to transducer-carrying platforms 208 a and 208 b, inthe FIG. 23 configuration, roll-permissive torsional beams 324 a and 324b connect directly to transducer-carrying platforms 325 a and 325 b.

FIG. 24 illustrates the point that gimbaling conductor configurationsmay employ torsional beams which are obliquely angled relative tolengthwise axis AX of the flexure. In gimbaling conductor configuration330, the axes of external torsional beams 332 a and 332 b, and internaltorsional beams 334 a and 334 b are each obliquely angled relative toaxis AX. The FIG. 24 configuration also illustrates the point that thetorsional axes of torsional beam pairs, i.e., 332 a and 332 b versus 334a and 334 b, do not need to be perpendicular to each other. These beamsperform as mixed-mode articulators, with both hinging and torsionalaction.

In FIG. 25, the gimbaling conductor configuration is similar to the FIG.14 configuration, except for the addition of longitudinal stiffeningarms 342 a and 342 b, each of which may be described as a simplysupported cantilever with applied moment. Ideally, arms 342 a and 342 bshould connect with 344 a and 344 b, respectively, as close to thecenter of the gimbal as possible.

All of the gimbaling conductor configurations mentioned so far, embody asingle pair of conductors. In contrast, FIG. 26 illustrates a gimbalingconductor configuration with four conductors 352, 354, 356 and 358.These form conductors are differently shaded in order to illustrate andclarify their respective paths from the flexure body into and throughthe gimbal. Each of conductors 352, 354, 356 and 358 contributes twotorsional beams and one quadrant of a transducer-carrying platform. Forexample, conductor 352 runs through torsional beam 352 a, then throughtorsional beam 352 b and ends in transducer-carrying platform quadrant352 c. Each of the other conductors follows a similar complementarypath.

FIG. 26 also illustrates that the four right-angle torsional beams shownin the FIG. 14 configuration can be replaced with four pairs of beams,wherein each pair includes two oblique beams. Each pair of obliquebeams, for example, the pair including beams 360 and 352 a, is referredto as a “triangular, dual-beam torsional articulator”. The triangulardual-beam torsional articulator provides greater stiffness in comparisonto the single right-angle beam systems previously described. It is alsopossible to produce a gimbaling conductor configuration in whichtorsional beams 360 and 352 a are parallel to each other.

The gimbaling conductor structure shown in FIG. 27A is fundamentallydifferent from the previously described gimbals because, here, gimbalingmovement is facilitated by hinges instead of by torsional beams. In FIG.27A, flexure 380 includes conductors 382 and 384. Moving toward thedistal ends of conductors 382 and 384, roll-permissive gimbal regions386 and 388 are defined. Nearer the distal ends, pitch-permissive hingeregions 390 and 392 are defined. FIG. 27B illustrates the distal endregion of flexure 395 which includes the gimbaling conductor structure380 of FIG. 27A, with the addition of top stiffening layers 394, 396 and398. Stiffeners 394, 396 and 398 stiffen all areas of the conductorsexcept for isolated hinge regions 386, 388, 390 and 392.

This hinging gimbal configuration provides several important advantages.First, it can be made smaller (less width required) compared to thegimbal configurations which employ torsional beams, and this allows moreof the disk surface, at the inner diameter, to be used for recordingdata since less pole-to-hub clearance is required. Second, aconsiderable amount of design flexibility is achieved withroll-permissive hinges 386 and 388 which can be positioned practicallyanywhere along the length of the flexure.

FIGS. 28A-30 illustrate another type of flexure which includes what maybe thought of as a gimbal, but which differs from previous embodimentsprincipally in that roll flexibility is achieved by the flexure bodyitself (i.e., by a “torsionally compliant beam”) rather than bytorsional beams or hinges, as in previously described gimbals. Threetorsionally compliant beams are illustrated. In FIGS. 28A and 28B, atorsionally compliant beam without a pitch gimbaling mechanism, isillustrated. In FIGS. 29A and 29B, a torsionally compliant beam isequipped with pitch-permissive torsional beams in the distal end of theflexure. In FIG. 30, a torsionally compliant beam with pitch-permissivehinges, is shown.

The first torsionally compliant beam, or flexure, described is shown inFIGS. 28A and 28B. Torsionally compliant flexure 400, from top view,includes three principal portions, namely, base portion 401, neckportion (also referred to as a “torsional compliance portion”) 402 andhead portion 403. In a preferred embodiment, base portion 401 has awidth W1 of 60-mils. Neck portion 402 has a width W2 of 20-mils. Headportion 403 has a width W3 of 40-mils. Conductors 404 a and 404 b(dashed lines in FIG. 28A) are adhesively bonded to overlying stiffeners405 a and 405 b. A hinge region 406 is defined by internal edges ofstiffeners of 405 a and 405 b. Three contact pads 407 a, 407 b and 407 care linearly arranged along the trailing edge of transducer chip 408which is bonded via solder structures 409 a and 409 b to the bottomsides of conductors 404 a and 404 b. Centrally located contact pad 407 bcontains the transducer pole. Only two of the three pads are necessaryfor the flexure to exhibit torsional compliance. For example, thecentral pad could be eliminated and the pole could be located in eitherone of the pads 407 a and 407 c. If the pole is located in one of theoff-center pads, it is preferable for the pole to be located in theoutside pad, i.e., the side of the chip which is closest to the outerperimeter of the disk, in order to maximize the amount of usable spaceon the disk. Alternatively, a pole can be located in each of the contactpads 407 a and 407 c. The two poles can be used alternately orselectively depending upon the particular situation. Flexure/transducer400 is shown with two conductors. However, it is apparent that a similartorsionally compliant flexure design employing four or more conductorscan be easily designed and fabricated.

A torsionally compliant beam must include the following interrelatedfeatures: (1) the neck portion of the beam must be sufficientlytorsionally soft to permit a desired range of roll movement of the headportion while maintaining sufficient lateral rigidity; (2) there must beat least two laterally-spaced contact pad points underneath the headportion of the flexure; (3) there must be sufficient load applied to thehead portion so that a line of interfacial contact between the contactpad points and the surface of the disk is maintained despite externalirregularities or aberrations which cause torsional flexing of the neckportion of the beam; and (4) the beam must exhibit sufficient lateral(anti-yaw) stability. Generally, as the distance between the laterallyspaced contact points increases, less load is required in order topermit a desired degree of roll movement. Preferably, a torsionallycompliant beam is sufficiently soft to permit plus or minus about 0.2°of roll under a total contact load of 300-mg. or less.

Note that flexure 400 is a gimbaling beam only in the sense that itpermits roll motion of the transducer chip. Flexure 400 does not includeany pitch gimbaling mechanism. The torsionally compliant beamsillustrated in FIGS. 29A-30 are similar to flexure 400, except theyadditionally include pitch gimbaling mechanisms.

The second torsionally compliant beam illustrated is shown in FIGS. 29Aand 29B. Flexure 410 includes load-bearing conductors 412 and 414 whichare separated from each other and extend the entire length of theflexure body. Importantly, the distal ends of conductors 412 and 414 areconfigured cooperatively to provide pitch gimbaling. Parallel distalcentral regions 418 a and 418 b of conductors 412 and 414 form,collectively, a platform 418 for mounting transducer chip 419.Stiffeners 420, 422 and 424 are laminated by adhesive (not shown), tothe top sides of conductors 412 and 414. Stiffener 424, laminated to thetop side of platform 418, leaves exposed torsional beams 430 a and 430 bwhich allow a selected range of pitch gimbaling of transducer chip 419.A triangular configuration of pads is employed on the working side oftransducer chip 419. One pad is located near the center of the trailingedge of chip 419. The other two pads are located at opposite rearcorners of the leading edge of the chip. Similar to previously describedgimbal designs, the three pad configuration defines an interfacialcontact plane between the transducer chip and the surface of therecording medium.

Importantly, for a given selected material, intermediate neck portion432 of flexure 410 is dimensioned (width, length and thickness) relativeto the distance between laterally spaced contact pads on the bottom sideof transducer chip 419, and the amount of load applied to chip 419, sothat the neck portion is sufficiently torsionally soft to allow adesired range of roll movement of the transducer-carrying platform,while maintaining the plane of interfacial contact between the contactpads and the disk surface so that a desired range of torsionalflexibility (typically 0.2° to 2.0°) for the transducer-carryingplatform is permitted. Ideally, the beam is sufficiently torsionallysoft to allow the transducer chip to roll approximately plus or minusone degree from applied moment due to the load. For example, flexure 410has the following specifications: the load is approximately 300- to350-milligrams; the width of the neck portion 432 of the beam isapproximately 20-mils.; the length of the beam from proximal hinge toits distal tip is approximately 350-mils.; and the transducer chip 419is 40-mils. by 40-mils.

The flexure 440, shown in FIG. 30, is essentially the same astorsionally compliant beam 410, except that a pitch gimbaling movementis permitted by hinges 442 and 444 instead of by torsional beams.

FIGS. 31-34C illustrate another set of embodiments of the invention,referred to as “dual-cantilever” flexures. In these embodiments, alsoreferred to as disk read/write structures, beams are stacked and spacedfrom each other by spacers located at each end. The overalldual-cantilever configuration may be referred to as a “parallelogramarticulation substructure”. Analogous to a “four-bar linkage”, theflexure can be flexed without significantly altering the angularrelationship between the transducer mounted on the distal end and thesurface of a recording medium. Dual-cantilever flexure 460, asillustrated in FIG. 31, has two sets of conductors and four hinges.However, the dual-cantilever concept could also be implemented in aflexure with one pair of conductors and/or no hinges. Flexure 460includes a top layer of side-by-side spaced conductors 462 and 464 whichare laminated by adhesive, as previously described, to stiffeners 466,468 and 469, with gaps 470 a and 471 a defining proximal and distalhinge regions, respectively. Stiffeners 466 and 469 are mounted on topof spacers 472 and 474, which in turn are mounted on top of stiffeners476 and 477 on opposite sides of stiffener 478. Stiffener 476 isseparated from stiffener 478 by a gap 470 b which defines a secondproximal hinge region in addition to 470 a. Similarly, stiffener 478 and477 are separated by a gap 471 b which defines a second distal hingeregion in addition to 471 a. Stiffeners 476, 477 and 478 are laminatedon top of conductors 480 and 482. The distal ends of conductors 480 and482 support and are mounted on top of transducer chip 484. FIG. 32 showsa perspective view of flexure 460, assembled.

FIG. 33 shows the unloaded U (solid lines) and loaded L (dash-dot lines)positions of flexure 460 relative to disk 490. Note that flexure 460 ispre-bent in its unloaded position, with most (ideally all) of thebending occurring in hinge regions 470 and 471. A notable feature of thedual-cantilever design is that equal and opposite bending occurs towardopposite ends of the flexure. Accordingly, as shown in FIG. 33,pre-bends in proximal hinge regions 470 a and 470 b are oppositelymatched by pre-bends in distal hinge regions 471 a and 471 b,respectively, so that transducer chip 484 maintains a parallelrelationship with disk 490 as it moves from its unloaded to its loadedposition. As shown in FIG. 33, by pre-bending a dual-cantilever flexure,an extremely close spacing between flexure mount 491 and disk 490 ispermitted.

FIGS. 34A-34C illustrate a modified dual-cantilever flexure which doesnot have any stiffeners, hinges or pre-bends. Thus, it is apparent thatthe dual-cantilever concept can be practiced beneficially in an unhinged(and non-pre-bent) flexure because one of the main reasons to use aproximal hinge, i.e., minimization of the angular constant of the distalend, is substantially achieved by the dual-cantilever linkage itself. InFIG. 34A, flexure 500 includes top layer conductors 502 and 504 mountedon top of spacers 506 and 508, on top of conductors 510 and 512. It isnecessary to provide electrical connection from the top layerconductors, for example, 502 and 504, to transducer 514 which is mountedon the bottom side of the distal ends of conductors 510 and 512. FIG.34B shows a perspective view of flexure 500, assembled.

FIG. 34C shows a side view of flexure 500 in its unloaded U (dash-dotlines) and loaded L (solid lines) positions, relative to disk 518.

The dual-cantilever concept can also be embodied in flexure designs withmore or less than four conductors. It is also possible to isolate all ofthe conductors in either of the top and bottom layers. It is sometimespreferable to isolate all of the conductors in the bottom layer becausethe distal ends of the bottom layer conductors are in better positionfor electrical connection to the transducer chip. For example, FIG. 35shows a dual-cantilever transducer/flexure 520 including top beam member521 spaced from conductors 522 a and 522 b by spacers 523 a and 523 blocated near the proximal and distal ends of the flexure, respectively.Transducer chip 524 is mounted on the bottom sides of the distal ends ofconductors 522 a and 522 b.

Still another dual-cantilever embodiment 526, as shown in FIG. 36A,includes two conductors 527 a and 527 b, each conductor extendingcontinuously over either the top or bottom layer of flexure 526. Nearthe proximal end of the beam, conductors 527 a and 527 b are separatedby spacer 528. A transducer chip 529 a is mounted to the distal end ofthe beam in an “on-end” or vertical orientation. As shown in FIG. 36B,chip 529 a is bound to conductors 527 a and 527 b by conductive epoxybonds 529 c and 529 d, thus eliminating the need for an additionalspacer at the distal end of the beam. Transducer chip 529 is mounted onthe bottom side of the distal end of conductor 527 b.

FIG. 37A illustrates a flexure mounting device which contacts andfollows the surface of the disk, thereby eliminating the need for apitch gimbal in the flexure. The device includes mount arm 532 attachedto pad 534 which contacts and follows the surface of relatively movingdisk 536. Flexure 538 is attached to mount arm 532, and supports, at itsdistal end, transducer chip 540 which contacts the surface of disk 536via contact pad 542. Assuming spacer pad 534 maintains contact with disk536, the height point 544 where the proximal end of flexure 538 ismounted, is maintained constant. By mounting flexure 538 on a mountingdevice which follows the contours of the disk, the need for pitchgimbaling is eliminated.

The transducer/flexure designs illustrated in FIGS. 37B and 37C relateto the mounting structure shown in FIG. 37A in the sense that contactpads are located on separate structures which are allowed a range ofarticulation movement with respect to each other. Generally, thisimportant feature of the invention makes possible gimbal designs inwhich the contact pads are spread out further from each other—resultingin greater surface accommodating stability. This is a contrast to thepad configurations previously described in which the distance betweenthe pads has been generally limited by the size of the transducer chip.

In FIG. 37B, transducer/flexure 545, near its distal end 546 a, has ahole 546 b for mounting, and a bonding window 546 c. A proximal hingeregion 546 d exposes conductors 546 e and 546 f which are also exposedthrough bonding window 546 c. Moving toward the distal end oftransducer/flexure 545, in an intermediate region, stiffeners 546 g and546 h are laminated on top of conductors 546 d and 546 f, respectively.Conductors 546 e and 546 f are again exposed in a second hinge regiondefined by spaces between stiffeners 546 g, 546 h and stiffener 546 k.On the bottom side of the flexure portion stiffened by stiffener 546 k,contact pads 546 l and 546 m are positioned near opposite lateral edgesof the portion. Conductors 546 e and 546 f are again exposed in a thirdhinge region defined by a space between stiffener 546 k and stiffener546 p. Underneath and toward the distal end of stiffener 546 p,transducer 546 q is mounted. A contact pad 546 r is located on thebottom side of transducer 546 q, near its trailing edge.Transducer/flexure 545 can be viewed as being made up of plural,articulated beam portions.

In transducer/flexure 545, the conductors in the second hinge region andlaterally spaced contact pads 546 l and 546 m, collectively provide forgimbaling movement of the transducer chip independent from the proximalend region of the flexure body. Pitch movement of transducer chip 546 qis made possible by the conductor hinges in the third hinge regionbetween the laterally spaced contact pads and the centrally located padat the distal tip of the transducer chip.

The transducer/flexure shown in FIG. 37C is similar to the one shown inFIG. 37B. Transducer/flexure 547, near its proximal end 548 a, has ahole 548 b for mounting alignment, and bonding windows 548 c and 548 d.Conductors 548 e, 548 f, 548 b and 548 h are exposed in bonding windows548 c and 548 d, respectively, and in a first hinge region 549 a. Movingdistally along the flexure, stiffener 548 i is laminated on top ofconductors 548 e and 548 f, and stiffener 548 i is laminated on top ofconductors 548 g and 548 h. The conductors are again exposed in a secondhinge region 549 b which is defined by the spaces between stiffeners 548i, 548 j and stiffener 548 k. On the bottom side of the flexure regionstiffened by stiffener 548 k, are laterally spaced contact pads 548 land 548 m (shown in dashed lines). Continuing to move toward the distalend of the flexure, the conductors are again exposed in a third hingeregion 549 c, defined by the space between stiffener 548 k and 548 n. Atthe distal end of the flexure, transducer chip 548 o (shown in dashedlines) is mounted on the bottom side of the flexure. A pole containingcontact pad 548 l (shown in dashed lines) is located on the bottom sideof transducer chip 548 o.

Each of the embodiments shown in FIGS. 37A-37C, illustrates importantmodification options relating to contact pad configurations. First,these embodiments (FIGS. 37A-37C) show that the contact pads do not haveto be formed on the chip itself, as they are in the previously describedtransducer/flexure designs. Second, it is possible to position one ormore of the contact pads on beam portions of the flexure whicharticulate independently from the flexure portion on which thetransducer is mounted. For example, in a gimbal such as the one shown inFIGS. 13-15C, the laterally-spaced contact pads on the leading edge ofchip 210 could be replaced on the bottom side of the roll framestiffened by stiffener 220. These principles make it possible toincrease greatly the longitudinal and lateral distances between the padswithin constraints due to size and disk waviness. As already noted,increasing the distances between the pads improves the operablestability of the flexure. Increase in the distance between the pads alsomakes it possible for the gimbal to perform under a lighter load.Minimizing the load, in turn, is important for the purpose of minimizingwear, reducing friction, and lowering the probability of head and/ordisk crash events.

FIGS. 38A-38C illustrate two flexure mounting systems. The mountingsystem illustrated in FIGS. 38B and 38C employ a dual-cantileverstructure resulting in closer disk-to-disk spacing in comparison toprevious flexure mounting systems, such as the one illustrated in FIG.38A. The flexure mounting system 550, shown in FIG. 38A, includes Eblock 552 supporting flexure mounts 554 a, 554 b, 554 c and 554 d, whichin turn hold flexures 556 a, 556 b, 556 c and 556 d, respectively. Theflexures are supported in contacting relationship with opposing surfacesof disks 558 a and 558 b. Because of the relatively rigid relationshipbetween E block 552 and mounts 554 a-554 d, in order to accommodatemounting and operating tolerances, a relative large spacing distance 560must be maintained between the disks. In contrast, the flexure mountingsystem 570, as shown in FIG. 38B, permits significantly closerdisk-to-disk spacing, by using a dual-cantilever in the mountingstructure. In flexure mounting system 570, E block 572 supportsdual-cantilever mounting structure 574 which has an elongate distal end576 connected to flexure 578, which end supports transducer chip 580 incontact with the surface of disk 582. Each of the other flexures in thesystem shown in FIG. 38B, is similarly mounted. Dual-cantileverstructure 574 allows relative movement between E block 572 and disk 582,while maintaining a parallel relationship between its elongate distalend 576 and the surface of disk 582. Accordingly, requisite disk-to-diskspacing 584 is greatly reduced relative to disk-to-disk space 560 in theprior system illustrated in FIG. 38A.

FIG. 38C is a magnified view of a single flexure mounting device fromFIG. 38B. The elongate distal end 576 of dual-cantilever structure 574supports pad 586 in a contacting relationship with the surface of disk582. The proximal end of flexure 578 is attached to dual-cantileverstructure distal end 576. By employing dual-cantilever structure 574 anddisk-contacting pad 586, dual-cantilever distal end 576 is maintained ina parallel relationship to the surface of disk 582, and at a constantheight above the disk. In addition to allowing closer disk-to-diskspacing, the design shown in FIG. 38C also substantially eliminates theneed for pitch gimbaling analogous to the system illustrated in FIG.37A.

Another aspect of the present invention relates to the goal ofsimplifying the process of mounting a flexure on an E block, and morespecifically, providing an easy way of connecting the flexureelectrically to a flex cable. FIGS. 39A-39C illustrate a flexuremounting structure which is versatile in the sense that it can be easilyelectrically connected to a mother flex cable in either an upside or adownside orientation. Nut-plate/flexure structure 587 a, as shown inFIG. 39A, includes a flexure 588 a which may take the form of any of theflexures previously described in this application, except for itsdifferent conductor structure. Nut-plate 588 b is welded by spots 588 cto a stiffener layer which is laminated on top of conductors 589 a and589 b toward the proximal end of flexure 588 a. Conductors 589 a and 589b run from the transducer chip through the flexure where conductor 589 apasses through the center region of the flexure and conductor 589 bextends along both sides of the intermediate portion of flexure 588 a.Conductor 589 b then passes under nut-plate, 588 b, and eventuallyextends in opposite lateral directions along paths leading to laterallyopposite, proximally located tabs 588 aa and 588 bb. Similarly,centrally extending conductor 589 a extends under nut-plate 588 b andeventually splits into separate laterally opposite directions on pathswhich end in tabs 588 aa and 588 bb. On tab 588 aa conductors 589 a and589 b are exposed on the bottom side, and therefore are not visible inthe view shown (dashed lines). Conversely, conductors 589 a and 589 bare exposed on the top side of tab 588 bb. Thus, if nut-plate/flexure587 a is mounted under an E block arm, electrical connection to the flexcable is accomplished by bending tab 588 bb up so that the conductorscontact the flex cable conductors. Alternatively, if nut-plate/flexure587 a is mounted on top of an E block arm, electrical connection isaccomplished by bending tab 588 aa down so that conductors 589 a and 589b contact the conductors in the flex cable. FIG. 39B shows fournut-plate/flexures, each one configured as shown in FIG. 39A, mounted onan E block. Nut-plate/flexure 587 a is electrically connected to a flexcable 588 d via conductor contact tab 589 bb. Nut-plate/flexure 587 b iselectrically connected to flex cable 588 d through conductor contact tab589 cc. Nut-plate/flexure 587 c is electrically connected to flex cable588 d through conductor contact tab 589 dd. Nut-plate/flexure 587 d iselectrically connected to flex cable 588 d through conductor contact tab589 ee.

FIG. 39C shows a modified conductor configuration that results inlateral tabs which facilitate easy upside/downside electrical connectionto a flex cable. Nut-plate/flexure 588 e includes conductors 589 i and589 j which extend from a gimbaled transducer mounted near the distalend of the flexure, through the flexure body, under the nut-plate, intosemi-circular conductor contact tab 589 ff, then to conductor contactpad 589 gg. On tab 589 ff, conductors 589 i and 589 j are upwardlyexposed. On pad 589 gg, conductors 589 i and 589 j are downwardlyexposed, and therefore not visible in the view shown (dashed lines).

The flexures previously described are generally designed to operateunder a load in the range of 30- to 300-, and preferably 35- to70-milligrams. It is important to minimize the load exerted on theflexure during operation in order to minimize the rates of head and diskwear and to lower frictional power consumption. However, for thoseflexures which include a gimbal, it is necessary to apply a load whichis great enough to maintain contact between the transducer chip contactpads and the disk surface, through the desired ranges of pitch and rollmovement. It is generally possible to upsize and downsize the flexuredesigns described in this application, for use under different appliedloads. For example, the load which is required for adequate gimbaling ofa given flexure design, can be decreased by lengthening and/or thinningthe dimensions of gimbal articulator structures, i.e., hinges ortorsional beams.

FIGS. 40A-40C illustrate a flexure which is designed to operate under aload of approximately 35- to 70-milligrams. Beginning near the proximalend of flexure 590, a hole 591 a is provided for mounting alignment. Awindow 591 b exposes conductors 592 a and 592 b for electrical bonding.Within proximal hinge region 591 c, conductors 592 a and 592 b are againvisible. The primary structural components of hinge region 591 c arestiffener straps 591 d and 591 e which are integral parts of stiffener591 f. Approaching the distal end of flexure 590, distal hinge region591 g is made up of lateral edge portions of conductors 592 a and 592 b.A gimbal 591 h is provided near the distal end of flexure 590 formounting a transducer and for facilitating movement of the transducerindependent from the main body of flexure 590. Three separate stiffeners591 i, 591 j and 591 k define gimbal articulators which are shown inmore detail in FIGS. 40B and 40C. Dimensions of flexure 590 are asfollows:

AA=0.060-inches

BB=0.455-inches

CC=0.030-inches

DD=0.010-inches

EE=0.350-inches

FF=0.080-inches

FIG. 40B illustrates an isolated top view of the conductors 592 a and592 h. The conductors are separately shaded in order to emphasize theirseparate paths. Stiffening layers 592 c and 592 d are co-planar withconductors 592 a and 592 b, but are separate from the conductors so theydo not function as conductors in flexure 590. Conductor 592 a extends tothe distal tip of flexure 590, then passes toward the transducer chipthrough torsional beam 592 e, then through hinge 592 f, finally endingin a transducer mounting platform 592 g. Similarly, conductor 592 bpasses through torsional beam 592 h, then through hinge 592 i, and endsin a transducer mounting platform 592 j.

FIG. 40C shows a magnified view of the assembled gimbal in flexure 590.As previously described, stiffeners 591 i, 591 j and 591 k expose anddefine gimbal articulators, namely, roll-permissive torsional beams 592e and 592 h, and pitch-permissive hinges 592 f and 592 i.Shock-resistant tabs 594 a, 594 b, 594 c and 594 d extend across the gapbetween stiffeners 591 i and 591 k. These tabs limit the distance orextent to which the transducer-carrying central region of the gimbal canmove upward along the Z axis out of the plane containing the rollstructure stiffened by stiffener 591 j. Similarly, tabs 595 a, 595 b,595 c and 595 d extend across the gap between stiffeners 591 i and 591j, thereby limiting the extent to which the roll frame can move upwardalong the Z axis above the plane containing the main body of theflexure. The primary purpose of the tabs is to limit the movement ofgimbal parts in a high-shock situation.

Miniature reservoirs for containing dampening material in and around thegimbal region are also defined. Each reservoir is typically formed bymaking semi-circular cuts on opposite edges of stiffeners near a gapbetween gimbal parts. For example, an outer organization of reservoirs597 a, 597 b, 597 c and 597 d facilitate deposition of a dampingmaterial through a syringe, for example, damping material 598 inreservoir 597 a, creating a bridge across the gap between stiffener 591i and 591 j. Two more damping material reservoirs 599 a and 599 b arelocated across gaps between stiffeners 591 j and 591 k on opposite sidesof stiffener 591 k. Hole 599 c in the center of stiffener 591 k isprovided to permit application of adhesive for the purpose of bondingthe chip to the suspension. Preferred dimensions in the gimbal regionare as follows:

GG=0.028-inches

HH=0.007-inches

II=0.024-inches

JJ=0.002-inches

KK=0.020-inches

LL=0.040-inches

MM=0.002-inches

NN=0.002-inches

OO=0.002-inches conductor thickness=0.004-inches stiffenerthickness=0.0008-inches

It should be noted with respect to flexure 590, as well as all of theother flexures previously described in which a hinge is located near thedistal end of the flexure, that it is sometimes preferred to replace thehinge with a pre-bend. Such a bend is in the range of approximately1°-4° around an axis parallel to the X axis (rotation of the distal endof the flexure upward out of the plane containing the flexure body).Fabricating a bend near the distal tip of the flexure is an extramanufacturing step in comparison to a process for manufacturing a flatflexure with a proximal hinge. However, a proximal bend is sometimespreferred over a proximal hinge because it improves vibrationalstability and is more robust to shock. For example, FIG. 40D showsschematically a side view of flexure 599 d which includes a main bodyportion 599 e and a distal end portion 599 f. The distal end portion 599f is slightly bent at point 599 g with respect to main body portion 599e. Angle α, i.e., the degree of pre-bending is approximately 1°-4°.

METHOD OF PRODUCTION

Various combinations of machining and chemical etching steps may be usedto construct flexures of the present invention.

EXAMPLE 1

Multiple sets of flexure layers are cut out of single sheets. Forexample, FIG. 41 shows a sheet 600 with four quadrants 602, 604, 606 and608. A set of laminated flexures is produced simultaneously in eachquadrant. The following figures and description focus on only a singlequadrant.

A 1-mil. layer of stainless steel is mechanically (laser) cut out in thepattern shown in FIG. 42. Cut-out section 610 defines the hinge, andcut-outs such as 612 form rectangular windows for wire bonding.

A second sheet of adhesive is cut with the same pattern as shown in FIG.42. If the adhesive is attached to the 1-mil. stainless steel layerprior to cutting, both layers can be cut simultaneously.

A conductive layer is mechanically cut out of a 0.5-mil. thick stainlesssteel sheet, according to the pattern 613 shown in FIG. 43, so that allconductors are electrically isolated after the final cut is made, asexplained below. The material is then cleaned and gold plated on bothsides of the sheet in region PP.

The alignment holes are then used to align the layers on tooling pins.The layers are pressed to specified loads and heated in an oven topromote curing of the adhesive.

The laminant is cut with a laser to define the beam shape 614 as shownin FIG. 44. The cut either defines individual beams 614 or “combs” 616of beams.

FIG. 45 shows a composite of all cuts.

FIG. 46 shows a final beam, essentially corresponding to the flexureillustrated in FIGS. 2 and 2B.

The flexure shown in FIG. 46 has the following dimensions:

A=40 mils.

B=20 mils.

C=350 mils.

D=390 mils.

E=430 mils.

F=24 mils.

G=10 mils.

H=12 mils.

I=21 mils.

J=44 mils.

K=60 mils.

EXAMPLE 2

The second manufacturing example employs chemical etching and/or lasercutting steps. Three sets of conductive layers are cut out from areas330, 332 and 334 of one sheet 336, as shown in FIG. 47. The followingdescription and drawings refer to the production of a single set offlexures from area 330. Alternatively, a continuous sheet of adhesivecan be applied, then cut out by plasma etching after the conductor andstiffener layers are laminated.

A 0.5-mil. thick stainless steel conductor layer is patterned as shownin FIG. 48. Pattern 340 is cut out either by chemical etching or lasercutting. During the production process, conductor pairs remain attachedto adjacent conductor pairs by tabs 342. A corresponding 1-mil. thickstainless steel stiffener layer is chemically etched or laser cutaccording to pattern 343 shown in FIG. 49. Adjacent stiffeners are heldtogether by tabs 344 and 346. An adhesive layer is applied either bystamping or laser cutting.

A 0.5-mil. thick layer of gold is plated onto the conductors. The goldmay be plated onto the entire conductor surface (preferred for stainlesssteel) or may be confined to the electrical bonding regions (preferredfor beryllium copper).

The layers are aligned and bonded under temperature and pressure.

Finally, individual flexures are separated from each other bymechanically shearing or laser cutting tabs 342, 344 and 346.

Other methods of producing laminant suspensions such as the onesdisclosed in U.S. Pat. Nos. 4,991,045 and 5,187,625 (both areincorporated here by reference) have been developed by HutchinsonTechnology Inc. of Hutchinson, Minn. and are generally applicable to theflexures disclosed in this application.

EXAMPLE 3

The following technique is used to attach the transducer chip.

Solder paste is applied with a stencil to the chip or beam (conductors).

The beam and the chip are aligned and the solder is heated to itsmelting point either locally with hot air, laser or infrared heating, orplaced in an oven.

EXAMPLE 4

Another method for attaching the transducer chip involves lasersoldering. First, tin is deposited on gold bonding pads on the chip.Second, a laser is used to heat the gold and tin through small holes(example, holes 90 in FIGS. 2 and 3A) in the metal (stiffener) or byheating the metal directly. The tin and gold melt to form a eutecticbond.

EXAMPLE 5

The following process is used to attach a damper for the purpose ofattenuating vibrations. Damping material can be applied either before orafter patterning.

In a pre-patterning technique, damper (viscoelastic polymer onconstraining layer) is stamped or cut with a laser to define the shape.Each damper is then aligned individually and then applied to each beam.

In a post-patterning process, a square of damping material withconstraining layer is applied to the beam or comb without precisealignment. A laser is then used to trim the shape of the dampingmaterial to be slightly larger than the beam shape.

Example 6

The following techniques are used to lap a single pad on a chip, forexample, 97 in FIGS. 3B and 3C.

First, the beams are made on a comb with relatively long fingers. Thecomb is placed in a “lapper/tester” machine which loads the beam onto arough disk for lapping. Electrical connection is made through the metalin these fingers (an extension of the beam conductors).

The machine individually twists the comb fingers and uses the magneticsignal as a lapping stop indicator to achieve “roll” facets.

Pitch facets are achieved by changing the Z-height and thereby changingthe angle at the beam tip.

Magnetic performance may also be tested in the process.

Example 7

The following technique is used for lapping a three-pad chip, such asthe one employed in the gimbaling flexures described above. Since thegimbal compensates for static tolerances, only a flat lap is required toachieve full signal quickly in the drive. Therefore, a shorter, simplercomb may be used with a simpler lapping machine. This machine loads thebeams to a given Z-height, exposing the pole and testing.

It is also possible to lap the chip pad prior to attaching the chip tothe beam.

FIGS. 50A and 50B schematically illustrate modified forms of transducerchips. In contrast to the rectangular transducer chips previouslydescribed, the chips shown in FIGS. 50A and 50B have different shapesfor the purposes of: (a) maximizing the lateral and longitudinaldistances between contact pads; (b) minimizing the weight of thetransducer chip; and (c) maximizing the efficient use of materials inthe chip-making process. The T-shaped and triangle-shaped transducers,as shown in FIGS. 50A and 50B, respectively, are particularly usefulchip designs where a tri-pad arrangement is formed on the bottom of thechip for use in a gimbaled, disk-contacting transducer/flexure. In FIG.50A, T-shaped chip 400 has contact pads 402 a, 402 b and 402 c arrangedin a triangular configuration. Similarly, in FIG. 50B, triangular chip410 has three contact pads 412 a 412 b and 412 c, again arranged in atriangular configuration. The shapes and dimensions of the chip are alsodictated by the particular coil structure which is typically embedded inthe chip.

Although numerous embodiments of the invention have been described indetail above, it is apparent that many other modifications are enabledby the disclosure and encompassed in spirit and scope by the claims setforth below. For example, while most all of the embodiments specificallydescribed above are transducer/flexures which are designed to operate incontact with the surface of a medium, it is apparent that many of theprinciples of the present invention have application to non-contactingor quasi-contacting transducer/flexures, such as “flying sliders”.Flying sliders do not employ pads such as the ones described in thisapplication, but instead employ rails or air-bearing pads. However,flying sliders frequently require gimbaling mechanisms, and face manysimilar mechanical accommodation challenges as do contactingtransducer/flexures. The fact that most of the embodiments described inthis application are shown with contacting pads, should not be viewed inany way as a limitation on the applicability of the present invention tonon-contacting or quasi-contacting head/flexure systems.

Further, it is important to recall that many of the features of thepresent invention can be employed to great advantage with mediums otherthan rigid disks—for example, with drums, floppy disks, tape, etc.

We claim:
 1. A disk-drive flexure/conductor structure comprising an elongate flexure body having a distal end including a plurality of conductors spaced from each other and extending along substantially the entire length of the body, and an electromagnetic transducer mounted on the distal end of the flexure body and held in dynamic contact with a recording surface of a magnetic recording medium amid read/write communication with said medium, and wherein each of said conductors has a thickness which is at least about 13% of the total thickness of the body so that the conductors function as load bearing beams at least partially supporting the transducer.
 2. The disk-drive flexure/conductor structure of claim 1 wherein the thickness of the conductors are at least about 20% of the total thickness of the flexure body.
 3. The disk-drive flexure/conductor structure of claim 1 wherein the flexure body has a proximal end opposite from the distal end, the flexure body having two lateral edges which taper inward from the proximal end toward the distal end so that the width of the flexure body near the distal end is less than the width of the flexure body near the proximal end.
 4. The disk-drive flexure/conductor structure of claim 1 further comprising a gimbal mechanism connecting the flexure body to the transducer so that the transducer is permitted to move relative to the flexure body during read/write operation on a magnetic recording medium.
 5. The disk-drive flexure/conductor structure of claim 1 wherein the flexure body has at least one location along its length where the conductors are the sole load-bearing beams in the flexure body.
 6. The disk-drive flexure/conductor structure of claim 5 wherein said location along the length of the flexure body defines a hinge region for permitting controlled movement of the transducer along a Z-axis perpendicular to a recording medium surface.
 7. The disk-drive flexure/conductor structure of claim 5 wherein said location is closer to the proximal end of the flexure body than it is to the distal end of the flexure body.
 8. The disk-drive flexure/conductor structure of claim 1 wherein the flexure body includes at least one stiffening layer adhesively bonded to the conductors.
 9. The disk-drive flexure/conductor structure of claim 6 wherein the flexure body includes stiffening layers adhesively joined to the conductors on opposite sides of the hinge region.
 10. A device for storing and retrieving information on a spinning rigid disk comprising: a transducer composed of a plurality of adjoining solid films including a disk-facing projection, a conductive coil inductively coupled to a magnetically permeable core terminating in a pair of tips encased by said projection for concurrent contact and communication with the disk, and an elongated arm attached to said transducer, composed of a plurality of adjoining solid layers and having a length, a width and a thickness with said thickness being substantially less than said width and said width being substantially less than said length, said arm including a plurality of conductive ribbons extending lengthwise, separated widthwise and connected to said coil.
 11. The device of claim 10 wherein at least one of said tips is exposed adjacent to the disk.
 12. The device of claim 10 wherein said conductive ribbons are disposed on a disk-facing portion of said arm.
 13. The device of claim 10 wherein said conductive ribbons are separated from other solid layers of said arm adjacent to said transducer. 